I think part of the problem is vertical storage, if that storage leads to air in your system and lines.
Yes, if grease, maybe even brake fluid, gets on the shoe linings, they'll grab and lock. No good way to clean it out.
Does the dolly have grease fittings to lube the wheel bearings? If so, pretty easy to over-pump with grease and bypass the inner seal. Or blow the seal, even the outer cap, out of its press fit to the hub.
Surge is nice because you don't need a controller in the towing vehicle. Better if several vehicles will tow it. Rentals are surge for that reason.
I'd have to see parts lists for Surge and for Electric Acme dollies to understand why you can't convert. Unless the "engineered" it that way for some obtuse reason.