If the EX codec is only 35 Mbps than does it do any good to convert it to ProRes LT or higher if Proxy is 45 Mbps? Proxy would save a lot of hard drive space. It would seem that the higher quality ProRes is wasting space because you can't improve on the original. Is this true?
Apple Certified Master Pro FCS 2
Personally, I don't deliver bitrates to my clients, I deliver images, and the better they look the better everyone comes out in the end. My point is, compare ProRes Proxy to ProRes 422 and use your eyeballs to determine if you see a difference. I know I certainly do.
Hard drives are now one of the least expensive components in your system, so don't cheap out on all the hard work that went into producing the great stuff you're working on just to save a few gigabytes of cheap storage. Use ProRes 422 at the very least and unless you're doing an offline. And, I say don't do an offline unless you're cutting 2K or 4K stuff, cuz I personally think do-overs are a ridiculous waste of time and a great way to potentially mess things up that you spent hours slaving to create in the edit.