I'd buy if

I’d buy Pureraw in a heartbeat if it would just handle my camera/lens combination.
I asked and they said it doesn’t.

Sigma 150-600mm f/5-6.3 DG OS HSM Contemporary
Canon 5D Mk IV

Welcome to the forum @GregM

You can request support for your gear on this page:

Don’t hold your breath, requesting a module does not necessarily mean that it will be released the next day or ever.

I have done that.
Thank you

Is there any problem with Pureraw reading the CR2 files my Canon puts out?

As long as you don’t use mRAW or sRAW compressed format.

You can check which lenses they do support on your Canon body here:

I wrote to them and asked and they said they don’t.

Yes, I saw that you’d posted that. All I was trying to do was show you how to find out if they do support any of your other cameras & lenses.