Nice synth.

I made an AUR package for helm (standalone, LV2 and VST) compiled from
the Git repo:

https://aur4.archlinux.org/packages/helm-git/

Thanks! Put my vote in.

Can the standalone version be compiled with JACK client support or is it
ALSA only?

Yea.. I think it's ALSA only right now. I assumed that JUCE built for JACK as well but I guess that's not the case. I'm looking in to this.