I have been using `git-branchless` a lot and really liking it. It should be part of the main git project, consider it a halfway between git and switching to some other tool.
These days, there are relatively few things that git-branchless can do that jj/Sapling can't, one example being its (somewhat opinionated) `git test` command: https://github.com/arxanas/git-branchless/wiki/Command:-git-...
Regardless keep up the good work. Assuming some one hasn't done it while I haven't been paying attention I will some day write some code to support gitlab in the submit command (I have a script I use all the time, just written around it rather than within).