I saw that same change in Dart’s code. It seems good, but if you miss that very first message, or you need to change the baud rate, it will say “no printer connected” for 20 minutes, or until you reset the board. There must be another good message to confirm that the printer is connected. Or even better, just fix M105 so it actually parses the message from a machine with EXTRUDERS=0.
What kind of controllers are you all using? Anyone using grbl? What about on Marlin, what boards and configurations are you using? I would like to support as much as possible, but I will be targeting the Skr pro first, and then the rambo, because that’s really common here, and for the most part, people with other boards know enough to manage it themselves. But I have a grbl board on my LR, so I wouldn’t mind getting that to work if it isn’t too hard. M106/M107 stuff makes me think you are all running Marlin.