The affixes khiṣṇuc and khakañ , when the word to be formed denotes an agent comes after the verb bhū 'to become', when it is in composition with the words formed by the affix cvi though not actually ending in the affix cvi,
Thus आढ्यम्भविष्णुः 'becoming rich (who was not rich before)'; आढ्यम्भावुकः 'becoming rich'; सुभगम्भविष्णुः or -भावुकः 'becoming happy'; स्थूलम्भविष्णुः or -भावुकः 'becoming big'; पलितम्भविष्णुः or -भावुकः 'becoming grey'; नग्नम्भविष्णुः or -भावुकः 'becoming naked'; अन्धम्भविष्णुः or -भावुकः 'becoming blind'; प्रियम्भविष्णुः or -भावुकः 'becoming an object of affection, amiable'.
Why do we say 'when denoting the agent'? Not so when it denotes the instrument. The affixes will apply when the sense of the upapada is that of च्वि, otherwise not; as आढ्यीं भविता 'he will be rich'.
These affixes will not apply when the upapada ends in च्वि; आढ्यी भविता ।,