Hi rd2rk:
How do you do to split the guitar signal before the Helix Input?
I have a Scarlett 18i8 as well, and I've been struggling to maintain it with the Helix, but as you say, as soon as you chose Asio Helix you lose the chance to use the Scarlett Asio Drivers and hence the Scarlett Mix Control, which is great for having set up separate mixes while recording.
I've simplified my equipment and left apart Scarlett which is simpler, though I've lost some possibilities.
Thanks in advance.