In most Boss pedals, you could get away doing true bypass pretty easily by removing the collector resistor that goes to the FET that bypasses the circuit so it will remain "always on" and re-rout the input and output + LED to a 3PDT switch. What about the DM-3? Can this scheme be used as well?
From a quick look at the schematic, I'd say yes.
BTW, FETs have a drain, a gate, and a source, not a collector, a base and an emitter like a BJT ("normal" transistor).
It's all in here.
Courtesy of R.G.
http://www.geofex.com/Article_Folders/bosstech.pdf
Edward B. - I know, I was referring to the BJT that also connects to the same junction.