When i do a quick start activity and then select a workout (60 mins today) there is an interval of the remaining hour on the quick start before I actually get to the selected workout.
No biggie as I can skip the interval via the fast forward button. Should the newly selected workout start straight away or is this by design?
This is by design, we put it at the end of the current interval. You have it right, skip is the trick.
I could break quick start into like 5 minute intervals rather than 1 60 minute interval and it would make that more simple/obvious.
Happy to remain as is, it wasn’t obvious at first but now know how it behaves.
It confuses me a bit too 
Meaning I merge and if I am zoomed in I don’t see anything. I think it is the best behavior currently for merging two workouts, just not best at the end of 60 minutes of quicksart.