Exactly! And nuke programs like these can not be entirely separate and standalone, so even access to known sites can shed info on some possible others, plus energy use monitoring and other things when inside.
Implementation and execution, not alone and subject to antics and charges and accusations, but with self-interested partners, all (or most) on one side of equation, with the other side isolated and no room for "mistakes". We are the "good guys" now. We can only do what's required of us to make this happen and make sure others are held accountable for their part of an agreement.
Like Reagan said after agreement with Soviets : "Doveryay, no proveryay" "Trust, but verify".