Simplier said than done, yet still: make "forcedBlockProtectionExceptionList", "blockProtectionOptionalExceptionGroups", "forcedEntityProtectionExceptionList" editable on runtime please.

It really is simpler said than done. I think it's possible but a lot needs to be done to handle the reload.
The simplest way to quickly test exceptions right now is on a singleplayer world, before copying the config file to your server.