I did the same update yesterday and it went without problems.
For me, I only disconnected the serial cable from 'ethm1plus' that goes to the control panel, and I plugged in the cable I had for programming the integra 32 (my version on the main board of the control panel is still in the older, 5-pin header). So it looks (and very good) that the 5-pin RS232 cable standard is the same in integra32 and ethm1 plus. I once saw a diagram of this cable in the manual (pdf) for the integrated.
All wires on the twisted connector 'ethm1plus' (power supply and keypad bus) are unchanged - they were connected during the upgrade.
Since I don't have RS232 in my laptop, I used a Chinese USBDB9 RS232 adapter. Interestingly, the "ETHM-1 Plus FLASH v2.03" program recognized it as com4, while in the system it is com10 (working with putty), but it works (the program sees ethm) so I did not touch it.
The program first searches for com devices and then upgrades, shows what it does step-by-step. It worked for the 1st time, the new version of the firmware was also detected by the android application connecting to this board, so everything went ok (full respect to the authors of this solution). I also didn't touch any slow/restart settings - the program went through the procedure itself. System: Win7.
What I don't know yet is: in the integra controll application I see only the manipulator. Numeric keypad, connects, works, but quite slow, so I'd like something more interactive, something like 'system dashboard'

- I look and see, without time-consuming scrolling through the keypad menu, etc. - During emergency situations it is necessary ...), and the other tabs (inputs/outputs/troubles/events) are greyed out. It looks like you may need to connect via the satel-server ('authorization' tab), but when I entered the mac+id of my 'ethm1plus' board, the server/application said yesterday that such a mac+id pair was not found. I also upgraded DloadX, and now I see that in mac+id they are already inflated, they do not show info, and they are not editable (while from the older version they were visible and editable). Today, in turn, I see that the application is trying to connect (not complaining about the lack of mac+id), but it gets stuck in 'downloading data'.
Maybe click something / somewhere to activate this connection (info on tabs other than the clean keyboard)? I hope I don't have to upgrade the integration software (currently I have 1.7).
Maybe someone can help?