xp0 usecase of stash: restrict to only use stash to save the unsaved work on any branch. so there shouldn't arise a need to have multiple stashes on the same branch. ideally here:
branches are semantically named
one branch houses alternative-implementations-of-the-same-contract (because alternative implementations need to be viewed side by side, maybe they should be just namespaced enumeration, and because only the best alternative should be kept, or we have not demarcated an alternative implementation well)
xp0 usecase of stash: restrict to only use stash to save the unsaved work on any branch. so there shouldn't arise a need to have multiple stashes on the same branch. ideally here: