in some patches I'm using the Helix also in 4CM with a Mesa dual rectifier (it has a pure parallel effects loop).
so, because I have a Helix delay block in the Mesa loop I need to mute the delay when it is bypassed (to prevent direct sound from both delay and mesa)
Actually I'm using a Volume block just before the delay set to volume 0 when on
then I'm controlling the bypass of both blocks: when delay is on the volume is bypassed, when delay if off the volume is 0.
this is working, but I'll try your suggestion as well because it sounds quite simple.
Anyway I think the mute in bypass should be a property of any block: hope to find it in a future release.