This would apply to both the RVD and RVD2 from my understanding.
I would use the Ring wirebound resister and a transformer rated for 8-24V AV (40V maximum) at 50/60Hz.
Does the 40V max mean 40 AMP max? as the doorbell supports 8-24v?
Would a 16v 10va charge slower than the Ring Pro 16v 30va or a 24v 20va?
What combination is the best for charging in a high use area?