Can you elaborate on how you use DeX specifically? I recently bought my first Samsung - and was a bit curious about it, surprised to hear that it is a powerful tool.
I use one of these https://www.amazon.co.uk/dp/B07YF95RNR, some bluetooth peripherals, and a little phone tripod. I have it set so that when a monitor is plugged in, DeX starts automatically, so when I'm at my desk and plug my phone in, in 2 seconds I'm ready to roll. I also use DeX with my AR glasses (Nreal Air) when traveling, which basically behaves like a full-HD monitor on your face.
My termux session runs permanently in the background out of laziness (though this does noticeably shorten your battery life, but it's been mostly manageable) so all I need to do is start AVNC.
There are a lot of little configurations and quality of life things that I tweaked over the past year or so of doing this; happy to write all those up somewhere if you're interested.
I spent some time last week trying to set this up.
You can use Andronix to install Linux and a window manager onto you phone. You then use a VNC app to connect to that (local) Linux container and you'll have a fully working Linux phone. Works pretty well, though I had to jump to a few hoops as not all distro's worked on my Fold 3.
DEX starts automatically when you plug HDMI into your (Samsung) phone. You then start the Andronix Linux container thing from DEX and you have a fully working Linux distro, right from your pocket. Pretty magical.
What I do, is use remote VSCode to connect to my dev server, so I don't need to run anything locally, because speed wasn't great for me. But if you set it up as I did, you can work from anywhere and you don't need a laptop.
Just a heads up, newer versions of Android will kill processes that spawn a certain amount of subprocesses. You'll want to look into disabling the phantom process killer using adb (works for unrooted phones but you need to repeat those steps after each reboot.)
My termux session runs permanently in the background out of laziness (though this does noticeably shorten your battery life, but it's been mostly manageable) so all I need to do is start AVNC.
There are a lot of little configurations and quality of life things that I tweaked over the past year or so of doing this; happy to write all those up somewhere if you're interested.