Nik.
I get ya. I think for me, it's a couple of things. *Wise old fucker mode*
1. I find Elixir Nanowebs to be about the most firm, tight, and articulate strings out there. Really. They give a smoothness to feel, but hold tuning and articulate individual notes better than any string I've ever played. There's lots of crispness, and tons of initial attack, without sounding 'cold' or sterile. I think those matter a lot, to avoid issues like intonation, muddiness, or "warbling' like you mentioned.
2. Part of it is technique, I suppose. I've learned the feel of the strings, and how to attack them. But in all honestly, an Elixir .068, at F, is remarkably strong, firm, and stable. Doesn't feel loose or 'spaghetti'-like at all. I wish I could let you play my 2027 and see for yourself. For years, I was actually always like, "Should I be tuning so low? Everyone says it shouldn't work with this setup." And yet, every time I played my guitar, it sounded and felt terrific.
I think it has to be experienced to really get it. I actually prefer the feel and sound of my guitar tuned to F, as opposed to A (whereas, I like my backup Squier 7, which uses different strings, tuned to A).