But this raises a question about which I keep forgetting. I was once IFRing
into Linden - an uncontrolled airport right next to Newark - in VMC. ATC
wanted me to cancel as early as possible of course, and I was perfectly
willing to do so. I just wanted to be below the class B first, but - at
least where I was - the floor was below ATC's MVA. So I cancelled, but I
felt a little odd being in class B having never received explicit clearance
into it.

Silly of me?

You were on a clearance when you entered Class B. That would be good enough for me.