I agree this might happen in more progressive dialects or future varieties of Klingon. Hypothetically speaking, of course. Someday we might have forms like {jIQongneHbe'} - and I agree that it would perhaps be slot #2.
In some natural languages it happened the same way: In Burmese the former verb <khyang> 'to wish, to desire' has become a grammatical verb suffix /-ʨʰin/ (pronounced [ʨʰɪ̃]) which just means 'want' and is sometimes just called "desiderative marker".
Maybe also the suffix {-nIS} used to be a verb with the meaning 'must' in the past? We have no evidence for that. I wonder if some has already written a HolQeD article in the olden days.
Of course this is all in-universe speculation about the language history of Klingon. But I find it very interesting too.