Longtime lurker, first time poster. I'm just so chuffed that this worked I wanted to share it with y'all.
I made the mistake of buying an M1 iMac without researching whether it would support Target Display Mode and of course it does not. I spent an hour on the phone with three different Apple techs, one who sent me a link to the support article about how to use TDM 🤦♀️, one who thought I could use Sidecar and one who told me that even if I bought monitors instead of trying to use old iMacs as displays, the M1 iMac *cannot* support two external displays 🤬.
This was pretty irritating because I have a three-screen workflow I do not want to give up. (My previous setup was a 2019 iMac, a 2012 iMac in TDM, and a VGA monitor). Support techs at Luna Display and Duet each confirmed that their solution would only support one other iMac as a display.
Well I tried both of them together, and was able to get each of them using a different iMac as a display, so both of my old iMacs are working as monitors now. 🎉 There is latency, more on the Duet than on the Luna. I'm okay with it. I have yet to see if this will remain stable through a whole workday, but so far it's working well even when I use the Zoom feature (screen enlarger, not videoconference). Which I do often. My poor vision is one of the reasons I want three big screens.
I hope this helps somebody else!
I made the mistake of buying an M1 iMac without researching whether it would support Target Display Mode and of course it does not. I spent an hour on the phone with three different Apple techs, one who sent me a link to the support article about how to use TDM 🤦♀️, one who thought I could use Sidecar and one who told me that even if I bought monitors instead of trying to use old iMacs as displays, the M1 iMac *cannot* support two external displays 🤬.
This was pretty irritating because I have a three-screen workflow I do not want to give up. (My previous setup was a 2019 iMac, a 2012 iMac in TDM, and a VGA monitor). Support techs at Luna Display and Duet each confirmed that their solution would only support one other iMac as a display.
Well I tried both of them together, and was able to get each of them using a different iMac as a display, so both of my old iMacs are working as monitors now. 🎉 There is latency, more on the Duet than on the Luna. I'm okay with it. I have yet to see if this will remain stable through a whole workday, but so far it's working well even when I use the Zoom feature (screen enlarger, not videoconference). Which I do often. My poor vision is one of the reasons I want three big screens.
I hope this helps somebody else!