That's what I was hoping. In practice I doubt you'd break them that much, unless you were doing another total UI rewrite, and it wouldn't be much effort to maintain them, at least compared to the effort of manually adjusting graph settings for 30 goals (which is apparently something someone is actually doing )
I'll consider, but I will need to check my policies at work and I think it'll be easier to get approval if it's an open source project (which a browser extension could be, whereas Beeminder itself obviously isn't at this time).
I wasn't even necessarily committing to actually build any browser extensions myself by posting this, though the idea has occurred to me more than once. Was interested in whether it had occurred to anyone else, and especially whether they got as far as actually doing it, even for something trivial.