Don't know about those.
But I have a "HOT-TAP" unit on ours.
Suits us fine.
Supply on demand. Set up by pool too when visitors around.

Got heater on pool at present.
31\33deg's. Luverleeeeee.
Costs around $32\35 p.d. but well worth it.

Just out of interest.
A mate of mine installs the Evac Tubes Home water systems.

we were talking. and he chatted his boss.

He's going to see about setting up a "small Evac Tubes" system for large vans and motorhomes.
(A More stable platform for trial).

IF it goes anywhere.

Anybody here with LARGE rig. Interested to having a coupla holes in his roof (Sealed)
and possibly free HWS system?. Will be FLAT to roof line.

Tiltable, "Maybe" if req'd.

Works GREAT at home. Haven't paid for hot water for near 10 yrs.
5 in house presently. Adults. Cooling of water not a problem
ALL hot showers. twice daily.

They heat water. CONTINUOUSLY while sun shining.
or any heat in air. Night or day.
With element in tank for dark periods of weather. (storms)