A/B/Y pedals

I'm probably wrong because I can't use real amps anymore in my current setup, but when I did I couldn't get this to work. IMO if you're going to layer, unless you have some way of creating really good isolation between the amps and more specifically the mics, trying to layer amps using an aby is a nightmare. I had far better results getting the best sound I could out of each amp, tracking them one by one in isolation, then blending them.

I'd be interested if other can do it this way, it seems like it could save a lot of time.

Anyway, I think the passive diy boxes are fine for the most part. The biggest problem I've found with them is switch bounce that probably won't be a problem if you're going to set and forget.