Ive just downloaded midiyoke and am about to play around with it.
Is it used for Triggering (for example) kontakt running as a standalone app rather than inside renoise?
If so can anyone share experiences of benefits/probs with doing this?
why should you use Kontakt as a MIDI application instead of a VSTi?
ther should be no benefit really: much less comfortable (you have to load Kontakt separately, load the correct multi, then load Renoise…), no performance gain (maybe it would be even slower).
I thought i might get some benefit out of triggering different ch from different tracks running in standalone mode and so maybe save a bit of cpu. I also sometimes move things into or reprogram in cubase or vice versa… and so a multi setup can be handy in some cases even with the extra issues you mention.
It wouldnt be worth the space and time itd take to go through how many probs cropped up when i tried to do this though 
headspinning.