App can still set their own beneficiaries rewards, we would just add SteemConnect fee on top of it within the same "comment_options" operation.

What if apps use max number of beneficiaries (as I know you can set like 8 beneficiaries at max) or 100% of reward values set as beneficiaries already?

I think the limit was increased to a larger number.

In this corner case we may not take fee.

So it basically means you alter the transactions send to your server before broadcasted?