So with original firmware, you can connect a DP cable to DP IN port from GPU and use TB3 to drive a monitor
but you can't do that with flashed firmware? Seems like a @CaseySJ question. :)
I know generally TB3 monitor support is tricky.
I concur with @TheBloke : other than annoying BIOS crash bug (which in my opinion is a non-issue as long as we know when it happens how to get back to normal.), my experiences with this build is fantastic. By no means, it's reliable as Casey's golden Z390/490 builds. But given we can have more...
This BIOS (F2 and F3c) is indeed buggy and I believe we all agree on that. Another thing I can think of is that do you have an USB SSDT so that only certain ports (plan to be used) are enabled? I have that SSDT and it boots fine.
Absolutely, The M1 price is very attractive considering the performance and low power consumption.
On the other hand, one reason the price is low is that M1 is a better version of A12Z which has been used on iPad Pro for a while. Not sure if they can maintain that if they announce 12/16/32/64...