I'm looking at Dali's internal measurements of the THD between their DD and an unnamed competitor (that's definitely legal CYA) and it's technically lower, but it's all below 0.1% 3rd order harmonic distortion (.... an odd choice vs THD, DDs all exhibit typically a lower ratio of odd to even order harmonics).

I found this elsewhere on head-fi, and this is more telling. Even mud across the whole spectrum totalling over 1% distortion is not ideal even for single DD designs, and this is not noteworthy over sennheiser's or beyerdynamic's offerings, let alone planar magnetic options from Audeze or Meze and nowhere near the incredible performance of Stax and Sennheiser electrostatics (those are closer to 0.1% THD across the spectrum). I wouldn't pay $1.3k for these.
This is of course just my opinion. I'm more experienced with IEMs at this point (I stopped buying HPs after getting a DT 1990 pro years ago), so if IEMs are an open option for you I can offer my opinion. If not, someone else might have input that can be helpful on the current portable HP market.
However, I will say one thing. I highly suggest you acquire a 7Hz x Crinacle Zero 2 to use as a reference for what clean distortion-free audio sounds like. It's honestly ridiculous that 7Hz managed to release such a reference quality audio product for under $25. While it's not the pinnacle of IEM performance due to the physical limitations of single driver designs, it does a damn good job of rendering clean audio.
https://www.audiosciencereview.com/forum/index.php?threads/7hz-x-crinacle-zero-2-iem-review.50534/
You can even turn these into a BT option using Fiio's BT adapters.