If your Galaxy S9+ ‘star2lte’ is ever to work with /e/OS ‘Q’, then a stock Android 10 must be installed first - no ifs, ands or buts unfortunately.
As has been repeatedly demonstrated, the prospective /e/OS user needs to be aware of all eventualities before switching operating systems. “When the child has already fallen into the well”, there is a lot of crying and of course the others are always blamed for one’s own misfortune.