I think the question is a good one. This question moves from technical, to theory and philosophy.
I do
not think the question is whether or not the Mega2560 processor is "good enough", as it has proven to operate many projects rather well, and will still do so when you pull your project from the barn in 40 years to show your Grand-kids. From that position more hardware advancement is not required to satisfy that segment of the community and applications. But not all issues are satisfied with speed and features. In-fact, none of them, without a world-class foundation to build from. Speeduino is very close to this level.
I
do think that expansion to envelop more projects, specialty applications, and future-proofing is a smart idea. While I would roughly estimate more than 80% of conventional EFI applications could be served acceptably with the Mega, that still leaves a fast-growing 20% that aren't or can't. This is the segment of users and applications that could be addressed moving forward. However, I do have an issue with expending substantial resources and efforts that direction - just yet.
I have said many times over many years, that Speeduino does not need to do everything - it has to do what it does
very well. To plant a flag on awesome, it has to be that, and growing more features and capabilities without optimizing the basic functions to awesome-level will be less than spectacular. You need a crack-free foundation to build a taller building. Speeduino deserves to be more than a yawn or mention in the field of EFI. This IMO is what is holding this project back from stardom at the moment, and preventing it from 'floating to the top'. It's OK, and yeah it works, but not universally recommended everywhere as "get Speeduino - it's awesome and if anything can run it well, Speeduino can." Any system looking to be world-class (or even survive) needs that status, and Speeduino is not exempt. I'm not here to find in 10 years they are saying "It's too bad about that Speeduino thing fading out." This
is future-proofing.
Speeduino is a firmware, not an ECM or hardware. Perhaps it's time for a tweaked v2. That firmware should be the best thing we can use to do the job. It should work as best as possible, for what it does, every time. Room for fairly minor improvements to the foundations has been stated all along, and I believe that is where energy should be focused, and
then on more 'cool stuff', including processors and features. From that perspective, it will not matter if it is running in a Mega, STM, or other processor, and that forward hardware and feature progression will then come naturally and quickly. All IMO, and I'm always open to different perspectives.