I like to use a DPDT so it’s easier to switch. Some effects with a Millenium circuit need a little help with the pull down to ground on the sense wire. A 1 Meg Ohm resistor to ground solves that problem. Otherwise it seems pretty stable and for what it’s worth, I think the version I was fine. The other option is relays. I’m running a SPST switch on my Reverb unit. The switch actuates a micro sized relay about the size of an IC that handles the true bypass. The switch also drives the LED. Eventually I’d like to put together a simple circuit that uses a momentary switch to latch a relay. I’m not sure if I’ll use a handful of transistors or use a chip for that yet. I haven’t put any time into it but I bought a bunch of momentary foot switches to do it with.