Pretty quickly, in the time it takes to drill 8 holes gor both pieces, 4 holes each.
Why did you need to buy a Beadlock system to drill mortises?
It is faster and more accurate than a dedicated mortiser.
Why not just use a drill press and fence?
It is portable like a dowling jig. Esentially it is a doweling jig. It can be placed most any where, where as a drill press has its limitations.
Can you
Yes
How about
IIRC no, so that would be 2 less than the Domino offers.
How much setup time is required?
Little to none. How much set up time does a doweling jig take.
Correct, not as quick as a Domino however a Domino probably only saves you
10 minutes for 20 mortises.