Only a clarification for the original question why the "plone.resource based resource path" is showing up. It seems the value key="compile" "False" flag is ignored. But this key is only useful if you specify already 'compiled' resources in the plone.bundles/onkopedia bundle with the jscompilation and csscompilation values and don't pass in any resources:
Because there's an 'onkopedia' resource in the bundle definition, the compile bundle step is still triggered and it needs to store it's compiled version somewhere. This can only be done in the ZODB (Zope security don't write to filesystem) in portal_resources (plone.resource). Hence the error.
Unfortunately plone.resource is only vaguely mentionned and never explained on docs.plone.org, but it's the intermediary zodb store where both compiled "resource into bundles" are stored (as the legacy bundle) and also the final 'combine_bundles' step (if you specifcy merge_with) for production delivery of the default and logged_in css/js.
I've stumbled my way through the resource handling in Plone 5.X this summer, one of the main issues I found is not that there are still some bugs left (there are) or the process is complicated (it is, inherent to resource handling) but that there was and is no 'high/mid level' overview documentation of how it is intended to work. (for which I have some WIP).