You could consider turning the process "on its head": Do release branches instead of a peer reviewed master branch. So you would have every developer continuo

You could consider turning the process "on its head": Do release branches instead of a peer reviewed master branch. So you would have every developer continuosly commiting into a (CI'ed) main trunk and when you wanted to do a release you would carefully review / quality assure the changes between the last release and the main trunk, taking only the stuff ready for release into new release branch and moving fixes back into the main trunk. This approach will give you a messier main branch (rather than messy development branches) and move the reviewing and QA till the time of release.