Thank you for your interest. I love my J1s, but it does have some quirks when used with octoprint. The two print heads don’t always play well together. Look at these posts:
and
I have not used copy or mirror modes. I have my left extruder printing with ABS, and the right extruder printing supports using HIPS. The 2nd extruder not turning off problem surfaced when doing a print that did not require any supports. In that case, T1 should not heat at all, but, it does. So, until I figure out a way to keep it from heating in the first place, I’ll just modify the ending G-code to make sure it gets turned off at the end of the print.