Accidentally pressed upload to SD via Octoprint instead of upload. Yeah, not sure why transferring a 3.5mb file would take 35 minutes to transfer via USB/Serial (at 200kbps). And of course cancel does NOT cancel the upload (but helpfully the slack plugin does message me that I failed to print). Given that I didn't want to corrupt the card, I let if finish, but ugh (welcome to 1992 modem speed)...
It's so slow because it's running through the whole gcode just for calculation of print time. I guess you can change that easily by modifying the source (I did not do yet because I don't need this functionality).
