Hey FoneBone, ok I get you now I think. My ideas here will be more general as I don't have direct experience with MP1 mod(x) or Boogie Rectifier(s). However, I do know MP1/2 quite well and have played along side plenty boogie users. Boogies are (in my experience) very middy amps generally (although I note the web site says the rectos have better bottom end, good thing...), they are also very touchy (getting the tone controls right) but are very articulate in the mids (their claim to fame maybe).
MJMP is the mod master, so if he says the 3.666 is the best MP1 mod for your sound choice, it will be.
Many of us ADAers go with scooped (lowered) mids which is more the Marshall sound (more my thing), to make a boogie sound you probably need to play/tweak with the mids and feature them a bit/lot. Boogie even have their speakers made middy, I've got boogie 90w celestion 12s in my ADA slant split stacks, they are way more middy than other celestions.
It seems the rectos are chasing much higher gain, as are the MP1 3TM mods, so then it's down to tone/eq etc., the MP1 has the basic tone shaping (B, M. T, P), using a decent analogue graphic in the loop is an option (recto has 5 band graphic ?) (BTW MP2 has 7 band graphic built in and shitloads of gain...).
Anyway hope that helps you thinking... Cheers R