I'm afraid I don't have an answer, I use JDBC regularly (admittedly , not Postgres and NOT using %XDBC classes) and I've never seen this behavior.
If anyone wants to dive deeper in this issue, more information are required to analyze and maybe try to reproduce it, like:

"....rapid increase in memory consumption by the IRIS server" What process is consuming memory? 
What OS, Windows or Linux? If Linux, what flavor?
What Java version are you using?
What version of Postgres  JDBC driver are you using?

Last but to least, note that class %XDBC.Gateway says:
"FOR INTERNAL USE - do not invoke directly"

LoadPageDir() compiles the subdirectories as well if/when in the Web Application definition the setting "Web Settings: Recurse" is flagged (enabled). (It's flagged/enabled by default when creating a Web App)

How is Recurse setting set in your "/CSP/ourapp/" Web Application definition/configuration?

Note that the directory you pass to LoadPageDir is in fact the path of a Web Application, not the physical path on disk.

I'm afraid it's not correct, for example the first item:

For ResearcherId the parretn 1N means "One Number", EXACTLY one number

I think the correct pattern should be .N, this means any number of Number (digits).

Supposing ResearcherId  is  mandatory and my contains only numbers (at least one), the the pattern would be 1.N

Last name would be 1.A, that is at least one low/upper case character

I don't think there is a limit on the number of Business Services a production may contain, 30 is definitely not a big number of BS, I've seen production with more than 100 BS and it works just fine.

Concerning the conversion of system Tasks into (scheduled, I guess) BS, well, it depends 😊

Depending on your use case there can be advantages or disadvantages, the main differences that come to my mind are:

  • Scheduled BS starts only if/when a production is started
  • When using mirror, scheduled BS runs only in Primary member
  • Scheduled BS run (start) only in the production namespace

Hi @Ariel Glikman, my bad, in the latest 2024-2025 "Healthcare Mirroring" documentation page I didn't see this:

To automatically configure and schedule this task, as well as mirror the HSSYS database, use the HSSYS Mirroring Utility.

Alternatively, manually schedule the task on each mirror member:

In fact until 2023.1 the (just released?! 😉) HSSYS Mirroring Utility  was only mentioned in the Upgrade documentation.