I never thought of playing it this way, but because selecting tiles and playing tiles are two different steps, it should indeed be possible to change the selection after revealing all selected tiles.

Because this will change the current flow of the game, I need to carefully add this interim step. I'll figure something out.

Thank you for your thoughts. I did not have much time to work on this unfortunately.

There has to be an extra step. There is no way around that. Only after all players selected a tiles the game engine knows about any disaster played. The engine needs to stop here and need to requests a decion of each player about "confirm selection" or "Undo move and sell tile".

But i think it is not that complicated anyway. First of alle, the new step is only required in a 3+ multiplayer when any disater is played. In that case, all city tiles in any players hand need to be discared, except the selected tile. Next, an information about the selected disaster must be displayed anywhere. After that, each player is activated again with all the options like in a normal turn, e.g. place tile, sell tile or reset placed tile. The only new logic required here is that only the previous selected tile can be placed or sold and nothing else.