Blockquote
Well what would really help is that canon releases the specs of the fileformat. as reverse engineering all bits of it seems to be quite time intensive and not yet fully done.
OK, that sounds much closer to the real answer.
It is a little surprising to me that it is hard to to reverse engineer, given that (a) raw formats are almost always very simple, (b) it is probably based on the predecessor CR2 format which is understood by RT and lots of other software and (c) there is software like the Adobe DNG converter that opens and converts CR3 files extremely quickly.
Now, to be sure, I don’t personally understand CR2, and it is has been a few years since I used a debugger to step through a program.
But surely there are others out there do understand CR2, and who can operate a debugger.
Obviously it would be better if Canon formally published a spec, but they have doubtless convinced themselves that the secret format is some big strategic advantage for them. Which seems silly to me, but I doubt that a letter writing campaign by camera owners will sway them.
I presume that Adobe wrote their DNG converter from a Canon spec, so they do share it with some people. Or maybe Adobe just reversed engineered the format.