Also not convinced there is anything to "Cash in on" here.
Most of the finescale societies (2mm, 3mm, S Scale etc) have produced their own plain track bases. These are all pretty similar, normally six sleepers on a web through which the rails are threaded.
The 2mm Scale Association's 8' 6" product is shown above. From memory the development of the tooling for these was a considerable investment that had to be backed by the product development fund financed by the society's membership subs.
The only commercial offerings that are similar are from British Finescale who offer a the above for standard N Gauge but for code 40 rails, finer than all commercially available track.
They do offer points kits in other scales 00, 00SF & EM but as can be appreciated these are all scales with a large following.
I doubt the interest 21mm gauge matches even the smaller of the specialist societies.
That's not to say it can't be done.
It just needs a co-ordinated effort and investment from those interested.