Hi - thinking about building a looper box with a couple of bypassable split/blend loops using lvlark's "Split'n'Blend" circuit. Does this seem like it would work? Is the 2nd 100uF filter cap unneccessary?
No I wouldn't worry about the second 100u cap, that will give you essentially a 200u filter cap and to be honest in something like this even the 100u will be mostly unnecessary.
You'll also need a cut between the gates of the first and second channel.