OpenGrok Docker Configuration Challenges

[exwindchiller]

I installed & launched OpenGrok Docker five years ago without much problem. I have reinstalled it on a new server and there is no end to the confusion on how to get it working. I have a pipeline job that updates the 650 Git repos in 150 projects hourly.
I would like to disable OpenGrok from trying to perform any git operations. I don't want it continually trying to reindex. I can reindex it nightly. The server has the same memory as the old one, which never had memory problems. The new server is getting memory errors. I have increased -Xmx, but it is not fixed. I think the problem is the configuration.xml has mergeCommitsEnabled for every repo, even tho docs say it defaults false. I have changed all to false, but something reverts them.

     <void property="mergeCommitsEnabled">
      <boolean>true</boolean>
     </void>

I found docs indicating there is a repo-wide setting to disable this, but it is not clear how. I can only find bits & pieces of docs scattered about. I have not installed the Pythons wrappers because I do not want to create conflicts with another Python sensitive process that runs on all repos. I also tried to disable the suggester to save memory, but none of the below read-only.xml seems to work.

<?xml version="1.0" encoding="UTF-8"?>
<java version="17.0.12" class="java.beans.XMLDecoder">
 <object class="org.opengrok.indexer.configuration.Configuration">
  <void property="Git">
     <mergeCommitsDisabled>true</mergeCommitsDisabled>
     <void property="mergeCommitsDisabled>">
       <boolean>true</boolean>
     </void>
  </void>
  <void property="suggesterConfig">
     <void property="enabled">
       <boolean>false</boolean>
     </void>
  </void>
 </object>
</java>

I am launching opengrok with: (I'm sure this contains many incorrect args, but I don't know what is correct.)

docker run --log-opt max-size=10m --log-opt max-file=5 -d --restart unless-stopped --name opengrok \
-e OPENGROK_SUGGESTER_ENABLED=false -e INDEXER_JAVA_OPTS="-Xmx5400m" \
-e SYNC_PERIOD_MINUTES=0 -e NOMIRROR=1 -e CHECK_INDEX \ 
-e INDEXER_OPT='-H -P -S -G -W /opengrok/etc/configuration.xml -i *.class -i *.jar -i *.zip -i d:vendors' \ 
-v /opt/opengrok/volumes/src:/opengrok/src -v /opt/opengrok/volumes/data:/opengrok/data \
-v /var/opengrok/etc:/opengrok/etc -p 8080:8080 opengrok/docker:latest

I am launching indexing with:

docker exec opengrok java -Djava.util.logging.config.file=/opengrok/etc/logging.properties \
    -jar /opengrok/lib/opengrok.jar \
    -c /usr/local/bin/ctags \
    -s /opengrok/src -d /opengrok/data -H -P -S -G \
    -W /opengrok/etc/configuration.xml -U http://localhost:8080 \
    -i *.class -i *.jar -i *.zip -i d:vendors \
    --progress

There a bunch of perforce errors cluttering the log. I would like to disable all repo interactions, except maybe git.