I see that someone marked a solution to this thread, but I'm not entirely sure you have an answer yet.
The wiim product names are confusing unless written in full. You refer to 'wiim pro' a few times, and I'm reading that as a wiim amp pro as you mentioned it in relation to the passive Elac DB63 speakers.
i.e. I'm reading that you have two setups:
1) the active Fives, that you possibly use for tv (from hdmi input) and for music via Bluetooth.
2) a wiim amp pro powering the passive Elac DB63s
So, back to the question, will an amp pro usb out to the Fives improve sound quality of that setup?
Compared to bluetooth, quite possibly, but it's not the right device for this.
A wiim pro streamer optical out to the Fives would be sufficient.