Like Sharon, I'm also curious about how your interpretation of paratva could solve the problem of the co-application of kāraka names that does not involve the concept of the left-right sides/parts: apādāna (1.4.24) vs. karaṇa (1.4.42), or karaṇa (1.4.42) vs. kartṛ (1.4.54), for example.  The utsarga-apavāda relation does not hold in these rules, unlike 1.4.45 and 1.4.46 you cited on p. 31 of your thesis, and hence ‘the apavāda tool’ cannot be used here to ‘identify the winning rule’.  At a cursory glance, you do not seem to have discussed these issues in your thesis, the issues which I think are crucial to your new interpretation of paratva.

Another simple impression is: if Pāṇini had intended what you said, would the rule have been formulated as . . . pare/parasmin kāryam ‘operation applicable to the right side/part’ instead of paraṃ kāryam?

With best wishes,

Yūto