Currently in the process of planning out exhaust mod. Initially I thought I could keep the OE backboxes, but the outlet on them is very much to the side of the car and the new Maxton diffusor/valence I got for quad tips would need a rather strong angle to the exhaust pipe to make it fit propely while also being balanced. I would prefer not to do a H style split since I expect the sideways branch will get less exhaust gas visually.
Both ideas look roughly like the drawing I made below. I for sure want to add a middle resonator to reduce the drone added from new DP without OPF. Vibrant 17950 was highly praised for MQB EA888 from what I could find. Another option would be an equally sized RM motors 01 silencer which should do the same job, but I found no real feedback on that.
Since the RM004/005 backboxes are straight through I'm not sure about the results and would have to just try it. But the quad tip design would be considerably more straight forward as they offer exactly the tips I want which could simply be clamped on to the boxes.
I don't know maybe I'm just talking myself into doing the full system by replacing the backboxes also

I feel the OE mod might not give me the result I actually intend so spending more initially usually ends up being the better idea in these cases than spending even more later to do what I initially wanted.
Already took off the original plastic to replace it with the Maxton but turns out the quad tip version just so slightly will not fit on the dual stock layout. It touches it on the outer edge and I decided to wait for now instead of putting it on to avoid risking melding or deforming it. Been driving around a couple days now without the diffusor like a clown

putting the original back seems daunting since it was a real mess to get it off.
Should be able to talk to an expert at the
shop next week.