FX Loop advice

[Stratotron]

Am looking for some advice regarding the Firehawk fx loop levels.

I am running a Fulltone Full Drive 2 as a boost in to a Line 6 M5 with the FX loop in and out set at around -7. I attempt to set the loop levels so the are at unity with the FH and let the device do the Boost.

I have experimented with the order of the 2 devices, this seems to work the best.

With the Fulltone off, any effect I have engaged on the M5 is weak, with the Fultone on, of course the M5 is robust, in some cases too much, and will occasionally "crack" at the high end of a cycle.

I have also moved the fx loop in front of the amp in the signal chain, it sounds more natural there, but can be slightly noisy depending on the gain.

As a routine, I have assigned switch 4 in the back row from reverb to fx loop, as I am writing this it occurs to me that I am not sure why? The rationale was that I never toggle reverb so don't need a switch dedicated  to that, hence fx loop.

 

So what I am after is some feedback on levels, device placement, and signal chain, in other words what are you all doing? 

 

As a side, I wish the FH had midi, so I could assign the M5 to switch with the device. I know, I know, don't tell me, the Helix has multiple FX loops and midi.....covering my ears...la la la la ...don't wanna hear it!!