Indeed it is uncommon and strange. Perhaps the strange thing with it is, being used to seeing {'oH} and/or {ghaH} with something definite, and suddenly seeing it with the indefinite suffix.

Anyway, as you pointed out, the need never arises to use something like it, so this question was purely theoretical.

And if I remember correctly, something similar may be happening with the simultaneous use of {-lu'} and {-wI'}. i.e. writing something like {leghlu'wI'}.

I think, in a thread here was said, that although *technically* it doesn't break any rules, it would be rather strange to say "someone/something who/which sees, but who/is is indefinite too".

~ bkbhkk