I use a TS OAG, normally with an ST-i, but that's in for repairs, so this trip it was a QHY5L-II. I suspect I could fine-tune the QHY more but I haven't found time to read any manual or docs and it worked well enough with my semi-random fiddling.
I use PHD or PHD2 for guiding and I do not use a ST4 cable.