Manifold Vacuum Experiment

If I have this correct.
After replacing the vac adv. idle timing was at 30 deg. connected to manifold vacuum. 20 deg. at idle w/ out vac.
After turning the adjustment screw full clockwise Idle timing increased to 40 deg. and idle time w/out vac remained at 20 deg.
Your observations were that the engine idles cleaner by a good bit and the engine has more balls at part throttle pulling up inclines.
Separating the two observed results. First the cleaner idle. I think this can be attributed to using manifold vac.
The second result, "more balls at part throttle", can be attributed to the full clockwise adjustment and a working diaphragm in the new vacuum adv. This second result would have still been realized even if the vac adv. was connected to ported vac. only.
Looks like your combination benefited from the changes you made so far.
Good job testing and tuning. Thank you for sharing.