this question may seem like a duplicate of How to automatically close NERDTree after a file has been opened? (which has excellent answers), but it's not, I swear. I'd like to extend the question:
I'd love for NERDtree to close after I pick a file with :e or with ctrlp.vim
In such cases, NERDtree remains open regardless of the let NERDTreeQuitOnOpen value.
How do I get NERDtree to close after opening a file, whichever way I decide to open it?