@folfdk @gambolputte @CiaraNi Tak for the tip! That looks interesting, I had not heard of it yet. Bookmarked!
I was thinking - but I haven't looked into it yet - that maybe there is some way to share a libre office file somehow. In that case some sort of cloud service could help. But it should be convenient and never confusing.
Tuta says that they are working on a "tuta-drive" service - but I have no idea when that will be finished and what it will look like.