In https://www.limesurvey.org/manual/Installation_security_hints, you
suggest running the following commands on a self-hosted instance:

$ chown -R myaccount:apache limesurvey/
$ chmod -R o-r-w-x limesurvey/
$ chmod -R -w limesurvey/
$ chmod -R 770 limesurvey/application/config
$ chmod -R 770 limesurvey/tmp
$ chmod -R 770 limesurvey/upload

The third command in this list, throws 20638 warnings (for 20638
individual filesystem objects), at least in our setup.
It is always the same warning, only the path and filesystem object name
change, e.g.:
chmod: limesurvey/.npmrc: new permissions are r--rw----, not r--r-----

Trying to enforce these permissions using
$ chmod -R ugo-w limesurvey/
instead breaks the installation.

Did you mean
$ chmod -R uo-w limesurvey/
instead or are we supposed to ignore the warnings?