DWC after reset may show you window offering to “confirm firmware reset” if this is the case increase “Reconnect Delay on Halt:” parameter in DWC. in my case 20 sec worked fine.
some other useful notes:
Q: DWC "Emergency stop button" behaviour.... is it equivalent to hardware reset pin 44 on expansion 50 pin slot? if not - what is the difference
A:No, it is a software reset, however it works very quickly - assuming that you have network connection of course.
Q: which pins out this 50 can be used for M581 ? reading wiring diagram did not help.
A:You can use any free endstop connector on the Duet. If you don't have a DueX board connected to the expansion connector, you can use any of the five En_STOP pins (n = 2-6). They are labelled on the underside of the Duet.