Cleaning up your history isn't hard if you think about building a clean-up-able history from the start, where each commit is a unit. At least it is easy for me. If it's larger and complicated, I create branchname-v1, branchname-v2, etc. branches and squash. Those branches will still hang around in my fork of the repo should anyone need them.

As for my personal projects, I recently realized that using leveldb wasn't going to cut it for me right before I finished the database storage feature. I still finished it to create a commit that didn't break the build and then worked on switching to rocksdb. If in the future I decide to switch back to leveldb, it's always there.