iM 4,1-14,4 27" 2010 iMac as "target display" works!

[Vladistone]

I'm trying to make an additional display for mac mini M2 be recognized (look at the screenshot - display LC-1011-2 11" 1920*440 HDMI-connected. It works fine, but is not displayed in the display settings window. I additionally installed SwitchResX (but maybe in vain, since I only managed to make it display in MAC settings once, by setting non-standard monitor settings... but now I have completely lost these tricks).
Can anyone help? Or suggest a source of knowledge in these manipulations with an additional non-standard screen?

 

[Shnite]

I got back to that iMac 2010 and put a fresh install of Sonoma 14.6.1 on it. TDP no longer works. It appears to flash once but unable to switch to the video source. I did not have to fiddle when it was on Monterey. Cmd F2 worked every time. Would be interesting to know if TDP works in Ventura, now that Monterey is sliding out of the end-of-life window.

I managed to get Target Display Mode (TDM) working on Ventura 14.7.8 (23H730), but it takes 5–30 attempts to successfully switch to the video source.
iPad Pro M1 -> iMac 27" 2010 (11,3).

 

[Nguyen Duc Hieu]

I managed to get Target Display Mode (TDM) working on Ventura 14.7.8 (23H730), but it takes 5–30 attempts to successfully switch to the video source.
iPad Pro M1 -> iMac 27" 2010 (11,3).

Would it be easier if you try getting TDM working on High Sierra?