The bus bar is another story and I see you addressed that in your design.

So, let me see if i got this right?

You are saying that the 2014 NEC addresses two cases w/o addressing the situation that involves both cases...........which is actually the case here and almost always the case.

Case #1 - you have PV backfed at the end of a conductor with no loads added or "addable"

Case #2 - PV at the end of a busbar.

In one case labelling req.s apply,

in the other, the much loved 120% rule (opposite feed then permitted at 120%).

So .....what we have here is a feeder conductor AND a busbar then the PV, so what applies?

It seems we can apply "the larger of the two" breaker req. to limit the feeder and the 120% rule SEPARATELY to the busbar.... - and we are golden?