Auto-generated qmldir files currently contain a preferred path that's hard-coded to point to the embedded qrc location.

There are some use-cases where users have resorted to manually removing the "prefer" line afterwards (see QTBUG-120435)

Those use-cases could be helped by allowing users to provide a custom "prefer" declaration (with the understanding that pointing to the non-default location means losing the Qt Quick Compiler optimizations). An empty custom path should result in no "prefer" declaration, in which case the warnings in QTBUG-138268 would apply.

Notes

• This suggestion is a superset of QTBUG-138268 so I've closed that one. Similarly, QTBUG-138421 might be a better alternative to this one.
• Unlike QTBUG-138268, this idea should be compatible with QTP0004 in general.