One feature that I've always thought would be nice is the ability to create an "empty" merge request that represents a new chunk of work. So even If I don't have a fork, as long as I have write access to a git repo, I can "Create Merge Request" and it will default to merging master onto master. This could immediately be updated to point to a branch of your choosing. Or maybe this flow could create a branch for you! Or you could leave it pointing to master and update the MR later. But having this option to arbitrarily create new MRs will streamline the process of embarking on new work. It has the added benefit of keeping all relevant discussion happening as close as possible to the work itself.
I believe GitHub has something similar to this, but I'm not 100% sure.