Woaahhh…just entered this forum and was asking @mia if I should open a thread about the flatpak so more people would be able to see it and ask for it, but what a surprise I’ve just when found this one that it’s almost 10 YEARS since it was opened!
Well, I’m one more asking for it cause I think it’s one of the feature request with most comments and people asking for it and the answer is the same I received by chat, that it’s been difficult, that the message will be sent to devs and that they will try again in the future 
No wonder why this topic is full of disappointed users that feel ignored but I’m pretty sure we love Insync in general and want to help, but the problem could be not to define an ETA (commit to it), cause it’s easier to leave it for later, that’s the principle of procrastination.
Anyway, thanks anyway @mia for being polite, but I think it’s time to take actions to do something different (if not, that’s the definition of craziness according to Einstein) and I say all this in the best way possible to inspire change cause I really like Insync.
PS: Thanks to all the others that have commented and tried to make this happen before, I’ve read all the posts.