Have the server broadcast "Don't forget to collect evidence by clicking F2 twice to take screenshots!" Or something along those lines every minute or so. This will encourage builders to take evidence during transactions in case they are scammed, which will mean less builders quitting due to being scammed. I see literally nothing that can go wrong with this. Oh, and maybe allow players to turn these broadcasts off if they don't like it. This more aimed towards newer players, so experienced players (who know who to turn the broadcasts off) won't need it.
As long as supporters don't see this, it seems like a decent idea. May get a little too spammy for new users though.
There isn't really a possible downside to this since they can opt out of it later so +1 for sure. But I think it would be a whole lot neater, address this and also solve about two dozen other issues if the tutorial was just redone with holograms and this was one of the points stressed in the tutorial with the holograms. It seems a liiiiiitttle bit lazy and messy to slap this in an announcement to cover tutorial's short comings but it is unquestionably superior to doing nothing.
If we throw this in the automated non-supporter reminders we already have I don't see an issue. Though I haven't seen those in over 2 years, so it could be there already for all I know.
