It's fine. I got the point, I use my own system now for backing up/restoring data, which works 100% reliably.
1:
Glad you have another way you find useful.
However, have you considered periodically taking/storing local backups and using Firefox Sync as well - using both ways?
There didn't appear to be a way to "roll back" to my old data using Sync.
Maybe that indeed isn't part of the Firefox Sync feature so far - idk - I'm not well informed about Firefox Sync.
Have you considered periodically taking/storing local backups to somewhat remedy that point and using Firefox Sync as well - using both ways?
2:
myriad of links that seem like spamming me information (...)
...
spamming me information (...)
Interesting concept, "don't spam me with your information" (made up quote by me). (Is that an actual accepted concept? 01, 02. Doesn't seem like an accepted concept/something that makes sense.)
3:
None of those links address the issues I had.
There's a reason some of the links I gave was about add-on/extension option in relation to Firefox Sync.
Also I wasn't even sure what exactly your issue/s was/were, hence I asked for clarification.
4:
Would have been interesting if fx you had only lost extension data, but not bookmark data. However that does not seem to be the case.
You probably meant "extensive" in your original post, although you somehow didn't make sure to make a clear acknowledgement about that in your followup post.
5:
When I went on reddit/Moz forums to discuss this sync issue with overwriting profile data (...)
Would you care to re-find those posts/threads and share them here? Could be informative/useful. We would be able to see how you described your issues back then when you were actually experiencing them atm.
6:
the number one voted response is "you can't expect Firefox Sync to backup extension, preference data! What are you thinking!" and I argue that that is a stupid perspective/position (...)
If you had read the links I provided in my previous comment, they actually have information relevant to that. Information that doesn't say "you can't expect Firefox Sync to backup extension, preference data", indeed they somewhat say the opposite - but you found that information/those links to be spam.
I'm not sure why you mention/care so much about what some forum members say when the official SUMO/Mozilla wiki links say the opposite. It seems you haven't read them - hence one could argue that information wasn't spam