Iv'e managed to script up some configs that would allow you to change the server when in game from gg_elimination to gg_deathmatch to normal gungame, however when you enable the .cfg it will load when the round is over. When you want to go back to normal gungame just use
So to add these files to your server just download and unzip the below files, located at the bottom of this post;
gg_elimination_addon.rar
gg_deathmatch_addon.rar
Then copy these files to the below directory;
Then add these commands to your rconlist.txt file
"DeathMatch Mode" exec gg_deathmatch_addon.cfg // Enable Deathmatch
"Elimination Mode" exec gg_elimination_addon.cfg // Enable Elimination
You can find the rconlist.txt file in the following directory;
cstrike/cfg/mani_admin_plugin/
I hope this helps, i am yet to find a way to have it auto change as per what you want but this is a start