New tag for the new kennel logic

The new kennel logic is the BuiltAt tags...
So if I want a unit to come out of a specific war factory, I would have to put BuiltAt on every unit for that side(or entire mod) to make sure no other unit will come out of that war factory, which is annoying if you as me.

Current way:

[NEWUNIT]
BuiltAt=NEWFACTORY

[OLDUNIT1]
BuiltAt=GAWEAP

[OLDUNIT2]
BuiltAt=GAWEAP

[OLDUNIT3]
BuiltAt=GAWEAP

...List goes on

This is very annoying and not efficient.

What I suggest is a new tag to make stuff easier: IsAlternativeFactory= boolean
If a war factory have this tag set to yes, it would not allow any unit to be built from it unless the unit have BuiltAt=ITS NAME.
It would work like this:

[NEWFACTORY]
IsAlternativeFactory=yes

[NEWUNIT]
BuiltAt=NEWFACTORY

[OLDUNIT1]
//No change required

[OLDUNIT2]
//No change required

[OLDUNIT3]
//No change required