I think this depends on what you want from your connection. Frequent re-syncs, whether you cause them deliberately or they happen as a result of line conditions, may well result in an increase in the noise margin target and/or interleaving, but that isn't necessarily bad. It will result in a more stable connection, and in my case that's what I wanted and have now achieved. I use a Speedtouch router now, and I've tweaked it with the DMT tool to increase the noise margin. Interleaving has been automatically applied, and that's good too as far as I'm concerned.
So it wouldn't be right to assume that the PN advice is wrong for everyone, but it needs to be qualified.
Eric