Yes, accepts a file too, but as the following test shows, it does not make any difference... a parsing error remains parsing error

USER>set fn="/tmp/mytest.json"

USER>open fn:"nw":1 if $test { use fn write "[0.1, .2]",! close fn write "OK" } else { write "Houston, we have..." }
OK
USER>write {}.%FromJSON(fn)

<THROW>%FromJSON+38^%Library.DynamicAbstractObject.1 *%Exception.General Parsing error 3 Line 1 Offset 7
USER 2e1>

So where is that forgiving Cache/IRIS version?

Do you have a code snippet for us? Something like

write mylist.%IsA("%ListOfDataTypes") --> 1
set item = mylist.%GetAt(2)
//
// Now the big question: what do you (want to) do with this item?
//
// do you try to lock a global: lock ^myGlobal(item) ?
// do you try to open (a possible locked) Object: set obj=##class(some.class).%OpenId(item [,4]) ?
// something else?

May I ask, which Cache or IRIS version you use?

USER>write $zv
IRIS for UNIX (Ubuntu Server LTS for x86-64) 2021.2 (Build 649U) Thu Jan 20 2022 08:49:51 EST
USER>write ##class(%DynamicAbstractObject).%FromJSON("[0.1, .2]")

<THROW>%FromJSON+38^%Library.DynamicAbstractObject.1 *%Exception.General Parsing error 3 Line 1 Offset 7
USER 2e1>

As you see, my IRIS is by far not so forgiving... ☹

Nice, now we know nearly everything, except the most important info: what is the content of pField?

I assume, pObject contains the above JSON, i.e.

set pObject = {"priority": "2",
               "lastmodifieduser": "PORTAL",
               "assignedto": "jdoe01 STAFF",
               ...
               }
               

Absolutely right. It's more readable,  without stumbling over millions of quotes and parenthesis during constructing (concatenate) the name of that globals ;-) 
I used the "string version" to show him/her, the global can be used even if the name is given as a string.

Somehow I don't understand your problem. If I create a simple class with a %Text property, insert some text data and then query for the word "time" I get it without problem.

Class DC.TextData Extends %Persistent
{
Property Comment As %Text(LANGUAGECLASS = "%Text.English", MAXLEN = 1000);
}

Now some data and the query

USER>d ##class(DC.TextData).%KillExtentData()

USER>s tt=##class(DC.TextData).%New(),tt.Comment="Notice, time is money." w tt.%Save()
1
USER>s tt=##class(DC.TextData).%New(),tt.Comment="It's time for a break." w tt.%Save()
1
USER>s tt=##class(DC.TextData).%New(),tt.Comment="There is no business like show business." w tt.%Save()
1
USER>d $system.SQL.Shell()
SQL Command Line Shell
----------------------------------------------------

The command prefix is currently set to: <<nothing>>.
Enter <command>, 'q' to quit, '?' for help.
[SQL]USER>>select $zversion
5.      select $zversion

Expression_1
IRIS for UNIX (Ubuntu Server LTS for x86-64) 2021.2 (Build 649U) Thu Jan 20 2022 08:49:51 EST

1 Rows(s) Affected
statement prepare time(s)/globals/cmds/disk: 0.0006s/4/140/0ms
          execute time(s)/globals/cmds/disk: 0.0008s/0/394/0ms
                          cached query class: %sqlcq.USER.cls7
---------------------------------------------------------------------------
[SQL]USER>>select * from DC.TextData where Comment %CONTAINS('time')
6.      select * from DC.TextData where Comment %CONTAINS('time')

ID      Comment
1       Notice, time is money.
2       It's time for a break.

2 Rows(s) Affected
statement prepare time(s)/globals/cmds/disk: 0.0005s/4/140/0ms
          execute time(s)/globals/cmds/disk: 0.0043s/30/4,322/0ms
                          cached query class: %sqlcq.USER.cls2
---------------------------------------------------------------------------
[SQL]USER>>quit

USER>

I know exactly nothing about healthcare, healthcare data, healthcare-classes and objects... sorry. For me it's a simple ObjectScript problem, where you try to do something (probably converting a dynamic object to its string representation - the above error message is known to me for this case). Does such a conversion occurs (somewhere) in your code?

There are no reserved words for %Contains but there is a requirement on the field (property) type. Excuse me for my arrogance, but instead of reading the documentation everybody thinks, it's cheaper to ask a question in the developer community, to get a ready made solution. So please read this first and if something is not clear, then tell it us what you do not understand and we will help you to understand.

Maybe there are tools to dump a dynamic object, I don't know, but you can always write your own short method

/// obj: a dynamic object
/// opt: an option, how to display array elements
///      0: just show the index number
///      1: show the parenthesized index
///      2: show index number in a %Get() method
/// tag: optional, the name of the <obj> variable
/// 
ClassMethod DumpJSON(obj, opt = 2, tag = "")
{
	set itr=obj.%GetIterator(), arr=obj.%IsA("%DynamicArray") set:tag]"" tag=tag_"."
	while itr.%GetNext(.key, .val) {
		set:arr key=$case(opt, 2:"%Get("_key_")", 1:"("_key_")", :key)
		if $isobject(val), val.%IsA("%DynamicAbstractObject") {
			do ..DumpJSON(val,opt,tag_key)
		} else { write tag,key,": ",val,! }
	}
}

For ease of use, put it into the %ZLANGC00.mac, for example

%ZLANGC00   ; Command extensions

// Dump a dymanmic object
ZDDUMP(obj,opt,tag) Public { do ##class(your.utility).DumpJSON(obj,.opt,.tag) }

For the data, you mentioned above, the following will be displayed

set metaDynObj={"versionId":"2","security":[{"system":"http://terminol....}

zddump metaDynObj::"metaDynObj"
metaDynObj.versionId: 2
metaDynObj.security.%Get(0).system: http://terminology.hl7.org/CodeSystem/v3-Confidentiality
metaDynObj.security.%Get(0).code: U
metaDynObj.security.%Get(0).display: unrestricted

zddump [11,22,33]
0: 11
1: 22
2: 33

zddump [11,22,33]:1:"x"
x.(0): 11
x.(1): 22
x.(2): 33

Why do you want to hide CSP files? That would be a mindless task.

Suppose, you encrypt your CSP (into fancy binary data). No browser would understand that! Browsers need plain text data. To hide the code on the server is also meaningless, you can read that CSP in the browser, that's the sense of a webpage .

For routines (*.int and *.mac)
- first, this is ABSOLUTE necessary, EXPORT your routines (to an file, to source-control-system, etc)
  for example: do $system.OBJ.Export(...)
- compile the routinies (which will be already done)
- delete the *.int and *.mac routinies keeping the *.obj

For classes (*.cls)
- first, this is ABSOLUTE necessary, EXPORT your classes (to an file, to source-control-system, etc)
  for example: do $system.OBJ.Export(...) do $system.OBJ.ExportPackage(...)
- compile the class(es) (which will be already done)
- put the class in deployed mode
  do $system.OBJ.MakeClassDeployed(...)
  
That's all. But DO NOT forget for the export, in elsecase you have to start over with your routines and classes by zero!

As I started with MUMPS, $H was a few days ahead of 50000, this means, I wrote my first programm (MUMPS V4b on a DEC PDP-11/34) even before ISC was founded. I have never made a direct use of those functions but, if a recall it right, they are used during the installation process (database creation, etc.) .  A quick look into the oldest docs I have (Cache 2.3) says nothing about those functions.

kill args
set args($i(args))="arg1"
set args($i(args))="arg2"
set args($i(args))="arg3"
...
set resultSet = ##class(%SQL.Statement).%ExecDirect( , sql_whereClause, args...)