Idea: A command (/LP user temp add permission.node . If the player does not have the permission node already, it will just add that much time starting from 0

You mean temporary permissions?

If yes, please check the wiki, since this already exists for LuckPerms. The command is:
/lp user/group <user/group> permission settemp <permission> <true/false> <time> [modifier] [context...]

The modifier you need is accumulate. If the permission does not exist already it is just added. The modifiers only matter if there’s a temporary permission of that node already (needs to be an exact match with permission and context).

So for the future, please check the existing commands before suggesting new ones.

Thanks for the quick response! I'll make sure to do that in the future :)