I have the exact same pick up combo in my Furch :-) I also have a looper and an OC3!
I play modern fingerstyle and whilst the K&K is great, just a little mic gives top end openess/air plus improves on the body percussion. The mag gives me a defined bottom end plus you can run fx through it that don't work too well with other sources, we have *very* similar requirements.
I have just bought the Bose T1 Tonematch to do exactly what you want - EQ/mix the sources separately, these are amazing value now they are being phased out, got mine brand new for the price they are going secondhand on EBAY.
I haven't had chance to rebuild my board yet and my guitar is having a pickup wiring issue sorted by my tech, so can't give you a full report. However, Mike Dawes uses a Bose T1 to combine an even more complex pick up and pedal board set up, and if its good enough for the acoustic guitarist of the year two years running (voted by UK guitar mags), who takes his board all over the world playing many different venues, its certainly good enough for me!
See here, Mike's rig and Tobias Rauscher:
https://www.youtube.com/watch?v=m8QjGM_Q7pM&t=271s
https://www.youtube.com/watch?v=5u5CUury0vE