Thought I’d leave this here.
I’ve serviced my Shimano T785 Dynamo hub bearings. I can confirm it’s possible to service the RH bearings. The key is dismantling the electrical connector to release the wire. After that there is a groove in the axle which you can push the wire into whilst you remove the cone. After that there’s a seal , then you can access the bearings and cup. The wire is more robust than others have made out, though if you are gentle it’s easy enough to access the hub without putting any undue stress on it.
When reassembling there is a circular piece of metal you insert into the electrical connector that engages with the connector body and groove in axle. This ensures the connector turns with the axle and protects from the wire getting pulled apart.
Screwing the cone back on with wire out the way in axle grooveShowing the groove in axle The connector fits to , to ensure it rotate in line with axle. Plus push wire in there when removing / fitting cone.
The parts of the electrical connectorThese easily prime apart with a brawdawl or similar. Photo shows left to right from locknut to seal after which you’ve reached the bearings and cup. The metal clip wires spring out / in to place. There is one part not shown in photo. The circular metal bit which fixes connector against axle. Didn’t realise it wasn’t in photo till after I’d finished,
Re assembled before tackling LH bearingsBut anyway it’s not that hard to service RH as well as LH bearings and easy enough not to worry about the wire if you take your time.