I see you posted this at several forums and still haven't gotten answer.

Might I suggest that you're not giving us enough information to make suggestions?

What version of Poser?  Operating system?

You say, I make a small change and the CR2 goes to 675Mb.  Can you please specify what this "small change" is?  Unless you've added a whole bunch of morphs, there is little reason to see this happen.  And, with every V4 commercial morph installed, you still shouldn't be seeing a file size like that.

Given the name of the Figure in your screenshot, it looks like you are using the Perfect V4 morphs, and if you've injected the "Upgrade" package, the literature on the marketplace page says "750+ morphs...."  That might do it.

Applying 750+ morphs is going to increase file size even IF you only clicked on one file to do so.