People that have trouble with dwell changes have likely the same problems today, as decades ago. They don't lube the rubbing blocks properly when they install new points. You can ruin the point contacts very quickly if there not opening as far as they should.
I used to use mostly Echlin parts back in the day, and they always supplied the capsule of lubricant within the package, as well as a diagram of what side of the rubbing block got grease dependent upon distributor rotation. Use that lube sparingly, too much and it can fling off on the contact points rendering them useless in short order.
The GM spec was 28-32 degrees of dwell, and as dwell increases as gap decreases I would always shoot for 28 degrees when setting it. As the rubbing block wears it increases, but stays within the preferred range for a longer time period.
Another thing that is key in ignition contact point life is keeping the contact points clean when using a feeler gauge to set them. I always wiped the blade off on the inside of my shirt before inserting it into the contact points. Likely a mechanics set of feeler gauges was also used to set solid lifter valve lash at some point, and residual oil will kill points very quickly.
When installing new points it is imperative for long life to make certain the contacts are square with each other and producing maximum contact area. Minimized contact area can lead to high resistance in a small area, quickly burning the contacts. You can bend the arm carefully to get better contact alignment.
Diagram below shows where to use distributor lube when servicing a points style distributor:
These were the basics taught to me by the old timers back then, if you followed these simple rules, the plugs would need replacement long before the points did. This is what makes a professional tune up, over a backyard shade tree tune up. It builds reputations, and a customer base. Also, same as now, cheap parts can bite you in the backside.
Accel used to be a Echlin company, and at the time were some of the best ignition parts on the market. With acquisitions of speed parts companies I have no idea if that is true anymore.