My vote goes to the middle one of the three code blocks you posted above, the one without the quotes. However I'm not sure if the actual driver should be "usbhid-ups" or "megatec_usb" - I would try the latter first (as it is shown in post #4 in that example file).
I'm glad it's not as easy as I thought, makes me feel a little less dumb...
Well, it isn't that it's not easy
- merely that neither of us has configured one of these before
and I for one have not read the entirety of the documentation; I expect that somewhere in the docs, there's a concise description of what's supposed to be done here -- and maybe not -- but if you can't find an exact reference, you'll need to test & experiment a little bit, or await someone who has configured the same software and thus has hands-on experience and been exactly where you are, before.
You'll get it sorted sooner than later I suspect.
- upon further thought, since you did make the symlink (yes?), I guess it would make sense to leave it like:
driver = usbhid-ups ignoreoff