Thanks for your reply!

I had tried using :perldo, and thought it hadn't worked (I was distracted by the "Variable length lookbehind is experimental in regex" warning, and didn’t notice that it had in fact run silently).

However, in this case I expect there to be false positives, and need to run it interactively; perldo it replaces globally without confirmation. Is there any way to get match-highlighting & confirmation with perldo?