FD.
Below are some examples of what increasing idle timing did. Many used vac adv connected to manifold vac [ MVA ] to get the extra advance at idle. I doubt MVA would work with your combo because the vac is likely to low to pull in the plunger on the VA unit. The engine will not care where/how the extra timing comes from....as long as it gets it. Locked timing is one method.
View attachment 1716484800
View attachment 1716484801
View attachment 1716484802
View attachment 1716484803
View attachment 1716484804