I would like to able to alter the presets (or add my own presets) to the presets dropdown while assigning rights to an object.

I need to set the roles for a lot of tables and they all need the same permissions.
An alternate solution would be manually running the task_role_tab_set_rights but I'm not really comfortable doing that without knowing the implications :)
For now I altered the def_role_tab_set_rights in SSMS to alter which checks are set by each of the 3 presets, fortunately I only needed 3 different presets.