I am looking into doing adding an M13 with my RP1000 also. Wondering if you've made any progress?
My current rig (from memory, so...):
TU-2->Wah->Wah->EHX B9->TS-808->DOD Octoplus->DOD Env. Filter->DOD SupraDistortion->RP1000->Amp In->
AMP (Fx Out) -> PH3 Phase->FL9 Flanger->DOD Chorus->RP1000 (FX In)
RP1000 (Fx Out)->Delay->EB Volume Pedal->Boomerang Looper->JHS Attenuator->AMP (FX In)
I'm thinking that I will use the 1st FX loop on the M13 and put it after the envelope filter and before distortion. Then 2nd loop after RP1000 (Fx Out) ---> M13 ->Delay->Volume.
Wondering if you or anyone else has any tips.
Go team!