Wheels are always a touchy subject.
Ultrascale now has a 12-month wait list and that actually increases the possibility of customers actually dying whilst waiting for their orders to progress up the queue. In many ways, they're a victim of their own success because, each time they manage to reduce the waiting time, word spreads, and more orders go in, causing the queues to lengthen back to what they were before.
AGW have no intention of tooling up for new types of driving wheel - realistically that kind of development stopped when Alan Gibson sold his eponymous business all those years ago.
Likewise I don't think there was any real intention of getting Sharman production going again - the production techniques and tooling were eccentric to say the least, and Steve & Angela Hodgson did well to keep it going in Wales for as long as they did before selling to Phoenix. The weakness of Sharman wheels is that the built-in crankpins are a fixed length; if you want to portray full thickness big ends on the driven axle, then they are not long enough.
Since RTR wheels are now much better at representing the appearance of the real thing, some P4 modellers are buying RTR driving wheels as spares, turning off the OO tyres on a lathe, and pressing the RTR centres into new P4 tyres; it's a lot of work, but if you want an accurate wheel for something like a BR Britannia or a 9F, then this is the only credible route.