The configuration cloudooo.cfg is generated via recipe.generic_cloudooo.
We cannot change the configuration file without breaking stack/erp5 because this configuration file doesn't fit the erp5 old cloudooo revision.
In order to make the configuration file overridable, I copied it outside the recipe, in software/cloudooo/cloudooo.cfg.in.
Edit: It was easier to change the recipe than to move it to a jinja2 configuration. I was stuck because cloudooo execution is not generic_exec (like slapos.recipe:wrapper does), it was execution_with_signal_translation which is not in any other "wrapper" recipe. If I want to use "wrapper" recipe, I need to modify cloudooo to do the signal translation.