I've been using this dex adapter for few weeks with S8 whilst Mac was being repaired
Recent Android Oreo update allows my S8 to work as touchpad, so no need for separate mouse (have had 2 GTs in the past and the previous version of it but couldn't really justify the price)
Can do dev on dex desktop using termux locally, or via aws Cloud9 running in browser, works pretty well. Linux on Galaxy will make it even better
Also ordered a portable 13" hdmi 1080p monitor from AliExpress which is powered via usb-c so very nearly have a fully portable setup, just need a decent & portable keyboard now, anyone know where I can get one?