HSM- Delay Intrusion Alerts. Clarification

Very occasionally my mode doesn't change away from AWAY quick enough when I open the door. All hell then lets loose. lights flash, announcements sound etc. etc.
I notice in HSM that there is a 'Delay intrusion Armed-Away alerts by this many seconds'.
My question is this.
If in AWAY mode and the door opens, which will trigger HSM, the delay by 30 seconds (configured above) will start.
If in this 30 seconds the mode changes to HOME, will the delay cancel and subsequently cancel any alerts I have set.

I could do this in RM4 but was just wondering how this works.

Now that you ask this question, I wonder the same thing!

I wonder as well

Not if you don't have HSM disamred in Home mode. HSM disarming is what prevents the alert, not your mode. They have to be tied together in the HSM app for this to not cause an intrusion alert.