How many 27" Thunderbolt Displays does the 2020 M1 Mac mini support?
Neither of those two suggested display configurations are possible, I'm afraid. You can only connect 1 of the 27&quot; Thunderbolt displays to the Thunderbolt 3 ports on the M1 Mac Mini. It doesn't matter if you daisy chain two monitors or plug them into each of their own Thunderbolt 3 ports - it still won't work.
The only way to natively hook up 2 displays to the M1 Mac Mini is to drive one display (and one display only) through the Thunderbolt 3 port and the other through the HDMI port. Obviously the 27&quot; Thunderbolt Display does not connect with the HDMI port.
When I say natively, I mean that it is ofcourse possible to use non-native display options - most popular would be a variety of DisplayLink products.
Adapters such as this do exist that converts the HDMI output to a USB-C style DisplayPort output. I guess you could plug a Thunderbolt 3 to Thunderbolt 2 adapter into that, but I doubt that it would work.