To illustrate the problem interacting from Nostr to Mastodon further: Here is a note originating from mastodon and I replied to it

nostr:nevent1qvzqqqqqqypzpv4j80wr3l4gu7938sksqfx66jj7gf5sml82eqdzul404y5458e5qqsq2sxg7tmpx5stu6qz3relmefm6srp504lp2t3rxv58226a6p4rxc964yl6

My response is one some relays but as I'm writing this it does not show up at Mastodon: https://mastodon.social/@neuimneuland/112296312651864213 

And if I look at my Mastodon home instance (I'm following that account!) 
https://res.social/@neuimneuland@mastodon.social
It looks like that user did not have posted anything ever. Hilarious!