Mike,
I agree with your sentiments about the car being on track and not kept off for what amount to insignificant things IN THOSE INSTANCES. The problem is that the way the IT rules are written, allowances like this can start an avalanche of similar requests. all cars have weak points, afterall.
it's a short jump from "replacement arm (mini)" to "adjustable arm" and "the updated part from the next specline of the same model car (Miata)" to "the factory's updated version that got used on another model (thinking Nissan S13-14 300ZX G45 and J30 rear ends)" to "my diff is weak, allow me something else entirely"
at that point, IT has morphed into something much more like the middle of Prod and ST, and there's no need for such a thing. IT's philosophy is there on purpose and the limited allowances in the rules, while they can certainly be an influence on winners and losers, are at the same time one of the main attractions to IT and a core reason the class is so successful.
yeah, it sucks when stuff goes NLA (some finned Aluminum brake drums). it sucks when a part from the OEM breaks regularly when raced on (1.6L OEM Miata diff). it REALLY sucks when that breaking part is NLA (MR2 and CRX hubs). I certainly don't want to tell someone to go away, but I'd certainly tell a guy who's out there having fun to figure something out and get back at it. Mark seems to have found that solution, and you are both right in that it's heavier and slower than the correct fix, and also cheaper. it's also likely that the person most upset about this is Mark himself.
but exceptions breed more exceptions. you start allowing stuff OFFICIALLY and you kill the category. Mark basically came out and said "I'm sick of my chit breaking, this is the fix that's within my budget and skillset, it's done, I'm not a threat to your championship, are you cool with that?" and I'm betting everyone on the grid said "yeah, that's cool." had it been an ISC car with an AC or JC piloting it, the reaction would likely be a bit less positive. Like when an ITB Omni shows up with no windshield wipers and metal headlight covers while overheating and running poorly - they have bigger fish to fry. yeah, they're illegal, but no one is going to do any more than point it out on that day. running for the lead, yeah, expect paper. the rules are preserved, the cars stay on track, and everyone is happy.
if you want to allow alternate whatever, prod and ST have you covered. IT makes sense as it is, deviations from that appear from my perspective to be a path to eventual demise, a death by a thousand cuts. will IT have issues to deal with when new tech cars become the norm? absolutely, as cars get heavier and more powerful we're seeing big heavy new classifications relative to the rest of the class. turbos and direct injection and the mainstreaming of variable valve timing will eventually need to be addressed in the rules or IT will be without new cars to class within the next 10 years. but the core principles will stay, I can promise you that. if that means a popular shift away from IT, then the category can be scrapped or repositioned. I'm betting that IT will remain healthy for a long time though, largely because we're so member driven and while a few are upset with a rule or protest loudly, the category continues to be one of the most subscribed by members who like the simple rules and low cost barrier to entry relative to so many other classes in W2W racing.