Any Advantage to Having a Dual Point Distributor for Daily Driver?

What total your trying to achieve? Block secondary points with a match or paper or ? and set the first set to spec, ie. 26. Then unblock the 2nd set and adjust it to get final dwell setting. The gap is what your changing. The 2nd set just extends the 'open' time, 26 can now be extended to 32 or whatever your chasing. IIRC they are ~9 out of sync by design so the same gap X2 would increase dwell by 9 degrees.