Are battery tanks for diving lamps still useful ?

[Valyngar]

Meant to add about that Scaleo power controller: looks like an excellent addition to the Santi drysuit connector. Hopefully it would be strong such that it doesn't break (as is the case for the Santi connectors)

It is really good. I and my buddy have used one for about 2 years. We have the integrated model and work was done in factory. They sell santi thermovalve too, so you can buy complete set from them directly.

 

[KevinNM]

Is it possible to buy an empty canister with a blank cap to use as a storage container for plb?

Yes. Call light monkey. They will provide a battery holder of whatever standard size you need without a hole for the wire drilled in the cap.