Adding internal FX loop to analog delay (madbean Man O' War, Maxon AD-900 clone)

[slowpogo]

I was going to build the Man O War from madbean, which is a Maxon AD-900 clone. I thought it might be cool to add a simple built-in phaser that affects the repeats but leaves the dry signal alone, as in an FX loop.  Madbean offers a Phase 45 clone in 1590A format which is quite small and might be made to work. The repeat phasing would have one knob and be switchable, either by a toggle or a footswitch.

Switching and enclosure issues aside... My big question is, where is the best place in the circuit to insert the phaser? Again, I only want it to affect the repeats. What about putting it after C35 but before the Mix pot?

https://madbeanpedals.com/projects/_folders/Delay/pdf/ManOWarDX.pdf

[PRR]

Is the FDBK pot in or out?