@Robert Guetzkow (rjg) Read my last comment please. I don't think it's invalid, but it's your forum, I will not change the status again
Feb 24 2021
I hope, from the bottom of my heart, that this time will be clear what I'm saying! No excuses, I have the blend file and a video showing whats the issue. Something changed in smoke simulations and I think is only when usining the INITIAL VELOCITY option. If this change was intentionaly, wasn't in the realease notes! But i suppose that it is not intentionaly once the fire and smoke simulation looks horrible compared with the last version of Blender!
Here I annex a blend file that was simulated at 2.91 and 2.82 AT THE SAME SETTINGS WITH A PROPER SIZE! If you don't belive me, download it and try it yourself!
Dec 23 2020
Dec 21 2020
See, in older vesions of Blender, Initial velocity has a lot more influence in smoke than at 2.91.0. Not saying that in newer versions the option has no influence, but it have an almost insiginificant one. Follow the image.