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Getting a Robofocus unit (assuming the spindle of your focusor fits the unit) and then using Focusmax is my recommendation. Though it all depends on weight being lifted. If you plan on lifting a very heavy payload then you will need to consider a FT focusor, FLI focusor or Belliphone focusor. For the average load though a rack and pinion focusor which is very beefy ought to work well.
I refocus after each sub with the FSQ. I have the programme slew to the zenith focus and then head back to the target. It takes about 5 minutes each time. I lose over the course of a night the equivalent of two 20 minute subs with imaging time. Worth it in my opinion. I don't image below 36 degrees, so I am only looking for high quality subs.
With the RC I focus once every hour. It does not change much during that time.
Focusing once or twice a night is not nearly enough for telescopes with a very shallow CFZ. Even a slight shift will result in an out of focus subs from that point on. I also recommend not using temperature compensation as it can be a little unreliable especially with regard to CFZ.
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