I always meant to make a Steam post about this, but unfortunately my graphics card died and I haven't had the time to re-research everything. But if somebody wanted to give it a shot (or, even better, write something up) I figure I'd get a quick post out about a couple of fixes I used to get around crashing on my (shouldn't have been based on the requirements) lower-end computer. It's important to note that one of these methods worked well for me, but I forgot which one in particular.
The first was to use in-game settings to force windowed mode, and then edit one of the ini files to force it to use a render resolution LOWER than what was possible using the in-game settings. On top of that, the display resolution was different, so you could essentially do whatever the opposite of supersampling is (upsampling? Upscaling?) as long as you could tolerate a blurry mess. I remember in particular that this would break the windowed mouse support for things such as the hacking minigame, and going to the video options would reset it unless the ini was protected.
The second was to use a framelimiter (like Nvidia Inspector or whatever it's called) to lower the framerate to ~30FPS. Actually the original idea behind this wasn't just to ease the stress on the card. The original idea was that if the port was a bit funky, it would target the original framerate for consoles, which is 30FPS locked. I should note that my card never got below 30FPS at any time normally.
Deus Ex: Mankind Divided still has crashes posted about today (including popular ones like the guard/subway area during the first hub) which I've gotten past. But, of course, no promises that these will work!