i have 2HP 2-spd pump on a 20,000 gal IG pool. I can offer these observations:
Pool cleaner will not work on Low speed (I have a suction side cleaner, StaRite Great White).
The SWG will work fine on Low speed.
The water movement on Low speed is amost undetectable on the surface (so skimmer is not very effective on Low). I have to put my hand in front of return fitting to tell if water is moving.
There is not enough flow (accroding to panel light) to run Heat pump when pump is on Low.

I have an Automated Controler (IntelliTouch) that lets me program when the pump goes to high speed - such as when the cleaner is On or if Heater is On. I believe you mentioned that you have automed control as well so you should be fine in this respect.
Good Luck