When you click once on the server, the "block" under the player list shows you the Version of SA:MP which the server is using,
if they don't realize the server is on 0.3d I would unfortunately have to say, their loss.
It's not difficult to run two versions of SA:MP, lets say 0.3d and 0.3e, just make two copies of your GTA SA, then install 0.3d in the one, while installing 0.3e in the other.