Many thanks to Stefan Baums for the additional examples phalāphala and bhavābhava. I find it interesting that so many (all?) of these reduplications with -ā- not derived from a verb root seem to come from Buddhist texts. Does this suggest a MIA origin of this feature?

Heiner Koch wrote:

yukti ayukti koṭa .....

sinhalese kara / koṭa = sk kṛtvā.

Any idea for translating yukti ayukti kṛtvā in a different way?

This is not my area, but would something like 'justifying the unjust' be possible?

Best wishes,
Martin