Each map can have a specific plugins.ini file for which it will load on map change.
This plugins file will be loaded in addition to the standard plugins.ini file.
Steps:
1. The file will be located at amxmodx/configs/maps/plugins-mapname.ini
2. For example, for zm_dust_world you would create the file amxmodx/configs/maps/plugins-zm_dust_world.ini
3. Then, just add tag "disabled" which will prevent this plugin from being loaded.
For example, if you want the map zm_dust_world to disable the plugin zp_extra_unlimited_clip.amxx and enable the plugin force_shield_grenade you would put this in amxmodx/configs/maps/plugins-zm_dust_world.ini: