I think much of the functions of many of theses labs can be privatized, as they already are managed & run by private contractors.
I know in the case of Los Alamos that only a fraction of the scientific time and resources are need for our top Secrete defense needs. Most of the time Lab scientist & resource are spent doing other things like researching Geo-thermal power, or testing theory’s of planetary formation.
The point is while we need to retain the resources & scientist for defense proposes all theses other things need not necessarily be on the tax-payers dime. We can “rent” the researchers time & resources.
As to where you put them, the property & equipment should legally be considered a military fort. For Constitutional & practical proposes. The Scientist and support personnel on the other hand should as a group be treated largely as they currently are contractors. Only DOD should be supplying the defense research & retention contract, and various other organization can bid on the in-between time & resources.
Certainly wouldn’t argue any of your points. One would think that perhaps the multi lab system itself could be made a bit smaller and more efficient. I did take notice of the Oklahoma lab which seems to me focused on alternative fuels.