I’ve never taken apart a Topre board, but looking at this video video, I’d say it was doable. Fiddly, maybe, but then again, so is opening up every switch on an MX board, too. Take your time, be gentle, pay close attention to what you’re doing… You’re probably going to be fine.

Same here, so unless something is fully open source, self hostable and preferably federating, I’m not picking it up.

Before opening up or resoldering any switches, I’d short the two pins with something (tweasers or similar) to confirm or rule out the switch itself as the cause.