Force enabling of usart on MDBT42Q breakout?

Both ways are possible, I tried both of them. just run Serial1.setup(9600,{rx:D8,tx:D6}); yourself at startup to always enable it. Right rx,tx pins are mentioned e.g. here

Removing that test shrinks firmware a bit and makes it more deterministic so that may make sense too. Also when it gets detected automatically the Serial1 object is missing ._options like when you run .setup() so you don't know the speed or that it is in fact enabled so that's another reason to setup it yourself so you know its state later in the code (e.g if you want to turn it off to save power and then back on when connection or traffic is detected like done here)