Pretty much what it says on the tin. To be a little more specific, I build a whole house, without bothering to worry about having smoothstone on hand or fussing with any bypass or turning things on/off, etc. Then when i am all done, I grab a bunch of reinforcement, and I use some special tool / chat command to click one corner of a cuboid and then click another opposite corner. it tells me the total cost of reinforcing all non-reinforced blocks in that cuboid, and I agree and it takes it all out of my inventory if I have enough on hand. Otherwise error message.

This is not an available option if there are ANY blocks within the cuboid that are reinforced by any group you do not have mod privileges on. So you couldn't use it to reinforcement grief somebody else's place. You can only do it to your own stuff or totally unprotected areas.

By the way, your inventory space limits this naturally to less than a single chunk or so at a time.

Also, should probably be same thing available but for removing a whole cuboid of reinforcements too -- in this case, it doesn't matter if other people have reinforcements in the cuboid, you can always just remove all of your own.

This would make it logistically like 30x easier to use citadel.