I wish you to add this procedure block to change gamerule.
For example: I wanted to create mod that could disable possibility for creepers to grief from begining survival game. I had some other ideas too. But this is impossible and command don't work without permission.
BTW. If "execute a command" procedure block don't work on survival mode and request permission, then such procedure block seems a totally useless for me. I don't see sense of this procedure since I can just type commands in creative mode and totally don't work in survival mode.
I think that commands triggered by "execute command" procedure block should to work always, regardless of permission of creative/survival mode.
I have recently found a way to execute commands with the biggest permission level. So in 1.9.1, it will be possible to run any command with server-level permission on any location or as any entity even if cheats are disabled and the command result will not be shown in the console.
You will be able to achieve this with commands in 1.9.1.