AFAIK all the fixes for the official maps are included in 2.4, the only exception being Goodwood-16 (and it
will be in 2.5, won't it Void?
).
If you happen to have problems with any of those maps, the fixes will work with 2.4.
The unofficial maps and the Lafette fix work with 2.4 as well.
If you want to use the GamePlayObjects.con (or GPO for short) files, you need to put them into the maps server.zip.
1.
Make a backup of the server.zip!2. Open the server.zip with WinRAR, then go into
'GameModes\sp3\64' and drop the new GPO file in. Then just close WinRAR, saving and updating the zip when it asks.
3. If you play Coop, you will need to repeat the above steps, but you'll need to put the GPO in
'GameModes\gpm_coop\64'.