My sequence aborted last night due to a lost guide star and SGP went through the end of sequence actions, parking the mount, closing the roof and disconnecting all the devices and those attached to PHD2.
It was a passing cloud and I manually opened the roof and hit resume in SGP a short while afterward. SGP connected all the direct equipment but it did not reconnect the devices back in PHD2. It also did not unpark the mount, slew or center again but immediately tried autofocusing on the observatory wall. I aborted again.
To get the system operating again, I had to manually connect all devices in SGP and PHD2, manually unpark, slew and center and then hit resume in SGP. (I also noticed that in my autofocus settings, although I do not have autofocus-on-resume enabled, it always autofocuses when I click the resume sequence button.)
It seems to me that in these conditions, it is unclear what is meant to happen. On the one hand, it would be great if SGP could entirely pick up from where it left off - just as it does when you run the sequence in the first place. On the other hand, it equally makes sense for SGP to decline a resume operation when the system has been aborted and the end of sequence options executed.
I feel that it has to be one of the other, at present the logic falls over.