Yeah, well, I would forget what post I wanted to make a reply to. Old guy. 
Even with a single mod note, it could sometimes be a problem with length. There is a maximum title length (I don’t recall what it is off the top of my head, but it exists), and some threads will already have a title that’s very close to that limit.
Meh. It could just mention the most recent one. That’s probably the one most vulnerable to being inadvertently missed.
Just keep clicking the multiquote button as you go through the thread…