Hi D-Sane,
I think this issue has been fixed with the C 11.010.
These are my EUcon settings in Cubase and I have the double tap on stop button working for me.
When I press the stop button twice the Play head returns to the position, I last pressed the play button.
This did not work in c11 as I was not able to change the Eucon settings. Now that Eucon settings can be edited again I unticked the Tape machine style transport checkmark and the stop button for me does what it did with older Cubase versions.
Hope I did not misunderstand your issue and this is the solution you were looking for.
Have a nice day