In the past, ROL have done some basic Select stuff for the Iyonix, which they've demonstrated on occasion. Just to show they're interested in doing work for the Iyonix, since it simply is a 'substantial' market for them to tap into. I don't think it's so much a 'political' thing, where they principally object to doing work for a rival or something.
Anyway, most if not all, 'Select' functionality we can clearly distinguish from RISC OS 5 are actually manifestations or surface extensions of quite deep rooted OS enhancements, going all the way to the core of the OS. What this means in practice, is that porting over our favourite Select / Adjust stuff to RISC OS 5 is practically impossible, since it would also involve altering or rewriting some core RISC OS 5 elements.
So, I think I can see how ROL are trying to make it possible to get 'Select' on the Iyonix; through RISC OS Six. Which means the criterion is basically reversed - now certain RO5 parts, like drivers or such like, would need to get ported and integrated into RO6 to get it to properly support Iyonix hardware. If that's done and working, it should be relatively straightforward to get Select 4 to run on it.
That's the idea of the situation I've got, though I'm sure it's not really very accurate. Furthermore, I'm not trying to excuse ROL for anything here, just trying to add a little perspective. In fact, I still think ROL have pulled some really rotten stuff in the past (even though they think it was for the best) and it's high time for them to clear up their website and PR.