I do some pro bono work for local teams related to my hobby. I'm afraid I would grow to hate the job and the hobby itself if it became real work.

How about something like making some open source or similar projects related to your hobby and having a patreon that people can support you with? Would depend how large and generous the potential audience is whether that would be enough to sustain you.

I'd caution against the non-profit direction! Some nonprofits that are inefficient aren't because they haven't discovered means to optimize processes or systems, but rather because of cultural issues...In addition to this add the low pay, plus lots of constant, hot air talk about whatever space the nonprofit operates in. I'm sure there are nonprofits out there that are ideal, and still have a need for expertise that you might bring them...but much like all other types of businesses, there are also many crappy nonprofit orgs out there. (I'm not referring to nefarious ones, merely ones that are run poorly and would not be great places to work at per your description above.)