Got my TMC2209s and everything is installed and working correctly. Note: The direction pin of these is inverted compared to the defaults. I set them up with 64 microsteps in stealth chop and adjusted the reference voltages o 0.15V. The motors are totally silent. So much that I forgot I had prints running. Tried setting the extruder with spread cycle but it had a horrible high pitch whine, so I went back to stealth chop. I had to increase the max PWM of the hotend a little since I was having trouble reaching >210° with the original settings.
I did have some problems getting the heatbed thermistor to recognize a good temperature. I see in the schematic that the new board uses a voltage follower, so I updated the config a little and I get ~30° ambient, and ~70° when hot, which I know is more like 60 but I can live with that.
Wire management is up next, but I've been having too much fun printing for that :D. I'm attaching my config file in case it's useful for someone.