well, too many things to consider when move from any much more popular RDB, to IRIS.

• first of all, most of such applications already uses some popular external programming language. when moving to IRIS, team would need to learn ObjectScript, and rewrite entire application from scratch. it will be mission impossible to to just easily switch application from using from MSSQL fro IRIS, cause MSSQL much wider supported, when IRIS not supported at all, except some community support which anyway is highly disapproved by official InterSystems.
• IRIS SQL is very outdated, any move from some modern database would mean moving back in 20 years. And will require to remove most of the modern SQL features from the application.
• even if you decide to write your own driver to iris that will be working with migrating application that will be considered as license violation.

You should raise this issue with IPM team, there are some work related to python, where it happens, and it could be related to intersystems-irispython official driver, which tend to fail randomly with segmentation fault, and this error most probably is comming from Python

A bit hackish way

{
  while IFS= read -r line; do
    echo 'write *27,"[1F",$namespace,">", "'$(echo $line | sed "s/\"/\"\"/g" )'",*27,"[1F"'
    printf '%s\n' "$line"
  done
} <<'EOF' | iris session iris
write $zv
write !,"hello ", $username,!
zn "%sys"
halt
EOF

and output

$ bash test.sh 

Node: e91a00f6512e, Instance: IRIS

USER>write $zv
IRIS for UNIX (Ubuntu Server LTS for ARM64 Containers) 2026.1.0L (Build 193U) Tue Jan 6 2026 01:46:47 EST
USER>write !,"hello ", $username,!

hello irisowner

USER>zn "%sys"

%SYS>halt