I'm just talking about history. I was a beta tester for CMD and even worked at their booth at the 1990 World of Commodore Amiga show in NYC. The show was rebranded Amiga only after CMD bought a both.
I was running animation at the booth of a 3D CMD HD off the RAMlink, and had to repeatedly explain... "It's coming from a C=64." when people who passed by were critical.
CMD was contemplating what peripherals they could sell for the C65. They were in talks with Commodore about making the Atari style parallel interface they used between the RAMlink and the CMD HD standard on the C65 for better drive access. So at the time I had a tiny bit of third hand inside knowledge on the project.
So the comments weren't mine. They were echos of the concerns of people inside Commodore at the time the C=65 was in development.
We were ALL real excited about the prospect of a 65816 based Commodore. Me in particular. I was actually one of the original forces behind the concept of a ZIPChip style accelerator for the C64 based on a the 65C02 and actually kind of inspired the SuperCPU, through I never owned one.
I am the "Joe Tom Collins" mentioned in the article. FYI.
That's why the SuperCPU went with the 65816. CMD had already done a lot of research on pushing the chips capabilities, in prep for the C=65 and was considering a CMD 65, for want of a better name, as Commodore was already past it's deathbed vigil by this point. So they recycled that research and made it an accelerator board for the existing 8 bits, overcoming some really absurdly complex obstacles that Jens Schonfeld of Individual Computer won't even TRY to address with his Turbo Chameleon.
I think he just didn't like the 128. He actually says plugging it into a C=128 will VOID YOUR WARRANTY!
If it wasn't for that, I would own one of those.
We were actually dreaming of a future with the WDC65C832 which never materialized as more than a data sheet.
I don't know what version of the C=65 the Mega65 guys are trying to recreate, but it's sounding less and less like the machine WE, and Commodore's engineering team were dreaming of back in the early 90's.
Which is perfectly OK. The fact that they Open Sourced the project is awesome, and FPGA's are now cheap enough and complex enough to allow any one of us to design the computer of our dreams.