I'm pretty happy with where they're at now, they're not perfect for every song but they are pretty dang close.
Only reason I would want to upgrade would be for something with better technical qualities like separation or clarity. That's not to say that they are bad at that, it's more just me wondering what's out there.
Mainly YouTube, their algorithm is pretty good about what I get recommended although I do tend to see some songs more than a couple of times. I find Spotify recommends songs that I've already got in a playlist far too often
I got the 64gb veraion and upgraded it within a week of owning it, would've done it sooner if the SSD had arrived quicker
I've had the blessing 2 dusk for about 2 years now and nothing has really seemed like a worthwhile upgrade to me. I'm sure you'll find a lot of praise for them on the internet so I'll give you what I dislike about them.
Entering the minds of weirdos
Super excited for Elden Ring and Cyberpunk DLC
Talking book saves a marriage
Androids having an existential crisis
Alternatively you can buy a replacement cable that way you don't have a large adapter that could become cumbersome, although it would be more expensive than an adapter. Decent cables go for about $20, I recommend Tripowin brand. Just make sure that it is MMCX to 2.5mm or 3.5mm. Be aware that 3.5mm will not be balanced but will still work with the Qudelix