I can confirm that the SPX-01 and SPX-02 have no end stop switches on either azimuth or elevation.
The Rot2Prog controller I am using with my SPX-02 quite happily remembers position when the power is cut (presumable writing to some non-volatile memory somewhere), so no issues there. Limits are set in the controller, based on the users cabling setup. In my case I have about 700 degrees of movement.
I would like to replace the Rot2Prog with something that does soft start and stop at some point. I investigated replacing it with the Spid MD-01 or MD-02 (same thing, bigger box), but the word direct from Alfa-Spid is that the soft-start functionality is only really usable with supply voltages >20V. It seems the PWM control it uses has some kind of fixed voltage limits, and so there is essentially zero soft-start effect when running at the 16V or so my SPX-02 needs. A bit of a shame really.
The Green Heron controller looks to be the business, but it’s extremely expensive - It would cost the same as the SPX-02, shipped.