I’m not aware if this is already available at faraway destinations e.g. truk, red sea etc. But wouldn’t it be less hassle if you could hire the bare bones of a rebreather, namely.
Cylinders (I know these are available)
1st stage valves
Lungs (open for discussion)
Mouth piece (may be)
Buoyancy aid bits and pieces.
Leaving you to bring what is really the business end of the rebreather and the thing you like to know the history of, the scrubber canister and controller + bov if desired.
This would allow easy travel without weight penalties. Maybe rebreather manufactures /suppliers would give good discounts for the supply of the above to rebreather friendly operator’s to encourage use of their units. I’m not sure of what cost would be attached for the hire but I wouldn’t think too much, as maintenance would be no different to open circuit.
My point being their would be very little outlay to the operator to purchase the above bits(compared with a complete rebreather) and the hirer would know the history of the controller.
Having taken my Inspiration to the red sea once to undertake my Mod 2 course, its not something you do lightly especially as weight restriction seem to be changing daily. I think the wife would notice that my case was filled entirely by my unit, however she may not notice the scrubber/controller. “Its my new snorkel thingy” would be how the conversation would go “just in case I get the odd few minutes to do a dive I mean snorkel”
So the question is would you rent?