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.
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.
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.