I can appreciate most of that (especially except the ability for a member to do it themselves) and as I said before I am expressing my admittedly biased vote/view/opinion and honestly don't know enough about a lot of models in IT to know or appreciate the effect on them.
There are members who can't tune their suspension on their own and still have a reasonable chance of staying in the same lap, they have to have someone else tune their suspension to stay on the same lap (and have someone else do it for their multiple track setups). If the requirement for the rule is whether or not members can do it themselves then the licensing requirements need not only mechanical knowledge but car preparation ability requirements added. The fact that some members would have to find someone to tune their haltech is not unreasonable (since some have to find someone else to do all their other car prep anyway) and it is a whole heck of a lot more reasonable than what exists now to squeeze it into the OEM case - there are far fewer members that can do that themselves or learn to do it themselves than learning the techniques and interfaces of standalone tuning. Your haltech example makes the existing rule all the more egregious, since right now very few would have the electrical acumen to utilize the existing rule.
If cars are classed based on the optimum level of preparation - then that assumption would include that it is classed assuming that an aftermarket ecu has been squeezed into the OEM box, correct? (or not?) That is a high expectation to arrive at the fully prepped car assumed in the classing of them.
(edit: I see your edit - I don't really care which way it goes a little more or a little less than what it is now. But at least we have a place to talk about it all openly!)
Or if it was readily available so most everyone could afford it, I'd be all for it.