Hopefully this will help someone else. I’ve had the same thoughts of it the powercab not being that loud, even for home use.
Im using a HX stomp and regular powercab. Output set to line level
I’ve just adjusted the Stomps Vol knob settings so it only effects headphones, (Global settings - Ins/Outs - volume controls) I’m now getting unity from the helix and the powercabs volume knob is right down rather than always needing to be so high (even at home). I’ve had to play with all of my patches via the master and Ch Vol in the amp blocks, but it makes much more sense now and works better for me. Muuuuuch louder too :)