Instead of implementiing all this multisig peculiar stuff, why dont you just change the 10% budget percentage?
It is obvious that the decided 10% budget percentage, this hardcoded number, does not fit to the needs of the current community.
And this happens to every hardcoded number that has no theory behind it.
This 10% must be voted. Must be voted all the time,in order to be able to change dynamically and fit into the community needs, and must be voted using numbers of course. I dont care whose task should be the voting of that number. But someone, some group of people, or even everybody, must have the power to change-vote this (and any other hardcoded) number.
That is all I have to say. You did a mistake by defining a hardcoded number 10% without a theory, and now you want to fix that mistake by doing more mistakes. Please keep the Kiss (keep it simple, stupid) principle. So the 10% percentage number of the budget has to change, and some people must have the task to change that number, by voting it.