It seems you chose the wrong license for what you are asking for. I see you spent time on this:

Re-re-license from AGPLv3 to the weaker copyleft OSL-3.0.
After spending too much time researching licenses, my laymen
understanding makes me feel that OSL-3.0 will be a better match given
TrailBase's rare dual use as a standalone backend or framework.

It tried to outline the reasoning in the README.md. I would appreciate
input from anyone more experienced with licenses.
For now, I would like to turn my attention back to more technical issues
:hide:.

I asked GPT-5.2 for a license recommendation and it says:

Clear recommendation given their exact wording:
MPL-2.0 is the correct license.

OSL-3.0 overshoots and contradicts their intent.
LGPL is awkward for server/framework software.
AGPL directly violates their first sentence.

Check it out https://opensource.org/license/mpl-2-0

FWIW, I personally would like to see MIT but you have your reasons.