Probably, I am too late to reply to this post, but I think it is worth anyway.
Mr. P.M., to me it sounds unbelievable that a business man like you has posted something like this, honestly.
I just hope this is a misunderstanding, as I imagine you should PROTECT the investment made by the Select-Scheme's Subscrivers and not waste their money on OS's features that the majority of Software Applications are not going to use.
I suggest you to release as soon as possible the low-level API to developers (let's be clear on this, I am NOT talking about apps like Paint or what is generally defined as complete software application).
A Select-Scheme's Subscriver for sure would like to see all the available software applications works better on his ROS Platform and see them to use all the OS's features. So, releasing the low-level API to every developer and every branches of RISC OS, is, probably, the best way to protect the S.S. Subscrivers' investment and wishes.
Moreover, from your own point of view, this is really good choice too, because improving the quality of available applications for RISC OS means to improve the value of YOUR work, not just in terms of fame, but also in economical terms, you know exactly what I am talking about.
Since the end of the "80's style computing" and the rise up of IBM PC's world and the Microsoft's business philosophy everybody knows that the value of a platform it's given by the software that runs on it and not by the UNUSED OS FEATURES.
Also Linux, and the Open Source world, is a "victim" of this business view, as Linux is evolving mostly by the enterprise's side than the Desktop users' side. This is due the fact that Enterprises are sponsoring the project "here and there", "forcing" the kernel's developer to optimize it for E.L. applications and the Linux Desktop sucks as a consequence of this world-wide behave.
The ONLY "blocking thing" for ROL about to release low-level API to everybody could be (if any) related to technical issues and costs related to make the ROS6's low-level features be able to work also on other ROS branches, but that's all.