Found an extension that does what I want without unpleasant side effects.
Lets me specify a site by URL from the discard list and persists between sessions without messing with discarding in general.
Interface a bit non-intuitive, but as long as you just have a particular sire or two and aren’t constantly changing, it’s completely unobtrusive.
So far. Will report back if problems.
Addendum: Not a problem from my perspective, but it saves its list as extension cookies, so careful do not delete.