Once there is enough of the code and tools in place to build an Iyonix version of RO5, it might not be a great deal of work to make a RPC compatible version of RISCOS 5.
So, the actual benefits of a RPC version are debatable but they do exist and it might not be a very difficult thing to do. I've no doubt that /some/ RO5 26/32 bit neutral RMs and support utilities will find their way over to the RPC.
I agree that making a RPC build of RO5 wouldn't be worth a *huge* effort at the expense of other projects.
Unless someone can correct me, I suspect it is possible to make a version of RO5 for the RPC which would boot in either 26 or 32 bit mode depending on user settings.
Obviously, the only other way that RPC users are going to get any RO updates is through Select.