Overbridge workflow using PC

I’m struggling with the whole concept of Overbridge and it’s usefulness to me in my setup and would welcome some input/advice.

I currently don’t have a soundcard so the idea of using my Analog 4 as the main brain really appealed to me. I run Ableton on PC Windows 10 and currently send my Model samples output into the A4 via the FX channels input.

My plan was to use the A4 as the soundcard but I will have to evaluate this approach as I’m planning on getting a Behringer TD3 in the new year and wont have enough inputs on the A4.
I dont want to start messing around with other software to allow use of aggregate devices etc as I just don’t want the hassle of dealing with the various issues that will bring on the PC.

I activated all four synth channels on the output side of the A4 in Overbridge as well as the input channels (model samples) and then also switched on the master input to send the results back into the A4 as it is acting as the soundcard for the whole setup.

It then became apparent to me that I could still hear the four voices of the A4 despite muting them in Ableton and after some fiddling realised that I needed to turn the internal audio routing off that was sending these 4 channels to the master output as well as Ableton.

It then became apparent to me that I could still hear the 4 voices if any FX was applied to them. So I have surmised that I’d need to turn the FX off each voice if I wanted to use them effectively in Ableton as if they were just another part of the Ableton track. I guess Ableton could handle any FX that was needed.

As of yet I cannot find a way to isolate the drums from the model samples by muting that track in Ableton. Not ideal if I want to use the A4 as my master soundcard.

This then brings me onto using Overbridge effectively in my setup. It seems to me that Overbridge is only effective if I want to use the A4 and only the A4 in my Ableton track.

As soon as I want to introduce the model samples or other gear then Overbridge can’t be used as I would need to send the Audio from the A4 into an independent soundcard along with the Behringer and the Model Samples which would all then route into Ableton.

My next observation is that to use Overbridge effectively in this setup is that if the sequencing is done in Ableton then the A4’s sequencer becomes redundant. I’m finding it all a bit confusing.

Would I be better buying a separate soundcard?
If I did use a separate soundcard, would I still be able to benefit from the midi side of Overbridge and still be able to route the A4’s audio into Ableton Via the A4 master output (not usb audio streams) along with all my other gear?

How would you run this setup?