Can I upgrade MacBook to Big Sur and still use an iMac in target display mode?

I'm opening this discussion up again (since the primary discusion -> https://discussions.apple.com/thread/252091987?answerId=254482836022#254482836022 has been closed), in order to share my experience.

I have a late 2009 iMac, running High Sierra, and a mid 2015 MacBook Pro running Big Sur (11.4).

I can confirm that target display mode does work for me (using my iMac as a secondary display). In fact I'm using it that way right now as I type. I use a standard mini display port cable to connect the two machines (this one https://www.amazon.co.uk/dp/B01CNOPIY8/).

I realise that this is in contradiction to the Apple tech doc which has been previously referenced (https://support.apple.com/en-us/HT204592)

My experience seems to fit with the 'update' within this MacWorld article https://www.macworld.com/article/348530/want-to-use-an-imac-as-an-external-monitor-you-need-an-old-version-of-macos.html, which impllies that it might be hit-and-miss.

YMMV, but if you have to / have upgraded to Big Sur, I'd say it's still worth giving it a try. I, in comon with many others, find this feature extremely useful and (for me) it has been reliable too.