An update, i borrowed an Apple Thunderbolt Display and various adaptors from a friend to do some testing and I managed to get my Apple Mini DisplayPort monitor running very poorly with the following setup...
M1 < Apple Thunderbolt 2 to 3 Adapter < Apple 27” Thunderbolt Display < LACIE TB Drive < Apple 27” Mini DisplayPort Display
The picture however looks jagged and full of chromatic aberrations, the resolution is terrible even if the monitor is properly recognised and the settings look right, and the main monitor loses power the moment the second is connected. I don't know what we can deduct from this but I thought of putting it out there.