I use similar H.264 settings but use Adobe Media Encoder to wrap a .MOV in a PDF file. The client can mark that up and return a very light-weight xml document as an .xfdf file. I find this so useful I do so when using other application to do the editing. A QT reference movie out of the editor writes very quickly and serves as the input to AME.
I should add that I’m running OSX and clients are various.