A.
UN 3536 Lithium batteries installed in cargo transport unit is a kind of high capacity large battery pack with battery control system, plus aironditioning and fire-supression system included and can be used for multimodal transportation.
The definition on Appendix A is reproduced here:

“Lithium Batteries installed in Cargo Transport Unit: －Typically this applies to lithium ion batteries installed into multi-modal shipping containers (cargo transport unit) where the completed unit acts as a large storage battery. The completed unit will contain lithium ion storage batteries plus battery management systems and may include air conditioning and a fire suppression system.”

By looking at Section 4 (blue pages of the DGR), you will notice that UN3536 Lithium batteries installed in cargo transport unit (containing lithium ion batteries or lithium metal batteries) is marked as Forbidden/Forbidden/Forbidden. In order to move these units by air, we need to follow DGR 1.1.2 (b) and abide with the rules outlined in DGR 1.2.6.1 “Exemptions” by securing approvals from the States of Origin, Transit, Overfly, Destination and of the Operator. It appears as though these units will have to wait some time to become popular and moving.