Just finished with it. Yeah, season 3 and the alternate was a bit much and especially the finale was quite fantastical imo. Still great though and will have to rewatch it again at some point to get everything. Probably would say it's my favourite TV series.
Martha and Jonas might have been the ones who caused Tannhaus family to crash to begin with, setting everything off in the first place - but similar to the Martha saves/doesn't save Jonas situation both realities exist at the same time and we only saw the one where Tannhaus family didn't crash
Probably I would have ended the show doing the former