With the former, the process would likely be contemplative, where the top business leaders, academics, and property owners would be elected as Electors, and they would gather and choose the persons most appealing to the state based on their diverse perspectives.
With the latter, each party in the state assembles a slate of partisans who are active in the party at the local precinct level. The majority popular vote in the state determines which slate of partisans is chosen as Electors. They would gather and vote by rote according to the party line.
Both methods pass Constitutional muster, but I suspect that the Framers expected the former process, not the latter one.
-PJ
IDK...
Much of their discussion seems to assume a State would ‘manage’ the selection of Electors to the State’s best advantage.