Having been down Rowter recently (23/11/17), I'd like to say a very big "Thank you!" to the BBPC and all those involved! It's a fantastic extension with very accommodating rigging and interesting sights.
For anyone interested in poking their head down there (which I'd highly recommend), this may be useful:
The trespass fee at the farm is currently ?2.
I used the rope lengths suggested by Mark in the first post, and they were bang on as far as I went ("Main shaft 70m, Gin shaft 15m, Badger rift 10m, Two Left Wellies 50m, Milky Relief 35m"). Although there is a ladder down Gin Shaft, it is made of wood and its current state will make the sensible go for a rope instead.
Deviations are not in situ, bring your own slings. In the medium-wet conditions at the time, it was easily possible to rig out of the water, with the exception of the very bottom of Milky Relief. If there is an obvious deviation, I must've overlooked it. If you don't want to get wet, there are two alternatives: There is a spit (no hanger) which was probably placed as a deviation (cannot miss it at the moment, cleared rock around it). Having brought no hangers, I went with option two: Approximately two meters above and slightly to the right of the spits there is a natural thread. To reach it you need to traverse very far from the initial Y hang, the consequences of a slip would be highly unpleasant. Position indicated on pictures below.
I can't wait to go back and explore the rest, unfortunately had to turn around at the Wizard's Sleeve this time as it was only meant to be a quick trip. Thank you BBPC for this great addition to Derbyshire caving!