From what I can tell since the latest update, v 1.2.170, which I applied this morning, it is no longer possible to attach the debugger to an already running DMEngine - started with a Ctrl + B or Shift + Ctrl + B. Attempting to do so comes up with an error message along the lines of Failed to attach the debugger…. Just hitting F5 and starting up with the debugger attached works.
A little gripe - after attaching the debugger one has to then simulate the device. It would be nice if it could all be done in a oner.