I came across this as I was aware I didn't really know that much about what I was trying to do - and bouldersoundguy over at HR mentioned "intersample peaking" on my last tune - a concept I was aware of but didn't really understand.
So I started re-mastering my CD masters with the concept of LUFS in mind courtesy of this and another loudness meter VST by someone called YouLean - https://youlean.co/youlean-loudness-meter/ - and I knocked out the first two songs without too much drama - the tools were useful.
But I got stuck and am still stuck, on the third one - which for the life of me I can't get to reasonable volume and not have peaking. Must have spent 4 hours on the damn thing yesterday. I'd flatten one transient peak out and the net result of that would be that the next highest one would then peak out. Very frustrating - especially as i can't actually hear the problem and it seems completely independent of the actual volume.
Think I perhaps need to try a different limiter. I'm using Stillwell's Event Horizon in limit mode and always have, but this particular song is just proving way too difficult - and for the life of me I can't tell what's different between this song and other songs - apart from this one having been recorded a little more quietly than the others.

Anyway that plug above is on a 14 day trial so I'd better get my head down on it. I'd forgotten I had to master at both 16 bit CD volume and 24 bit streaming / MP3 volume, and that the two aren't remotely the same thing. Lots of interesting stuff out there on how the streaming services treat "loud" mixes too... probably why my previous album sounds not so hot when streamed and on the CD Baby YouTube vids.