I went against my own rule...

ITs too late, he's got the cupboards and shelving already anchored in.
If it’s not glued down couldn’t you just cut it at the base of the new shelves and vanity? If the old stuff was glued down good you would have no worries really but if its loose it’s possible you’re new flooring going on top is going to feel loose or you might have a sound of some kind that’s going to drive you nuts because you’re going to know exactly why it’s happening lol
 
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