There is a way to help, that I'm going to try apparently.
First, you turn off the restrict mode, but first of course, you have to bring up the comand line:
This will disable the restriction and allow you to type codes.
Now type this:
This should stop streaming of textures, and will load all the textures from a cache, hopefully stopping the problem of popping up happening. I haven't yet tried it enough.
Pop up of bushes/grass also annoys me in this game, but I'm sure they'd be tweaks to fix that somewhere too.
The best way to do these setting changes is to create a system.cfg in the Crysis folder, and to type the commands here, and then save it. When the game is loading, it'll search for this file, and allow the changes. Mine goes like this now, and is the minimal DX10 hack to allow the most visual of effects to appear: