Can you cite some links to support that? This was discussed a few weeks ago on a news program and they said what I wrote, If that was wrong, I’d like to see some support for your contention that a voter votes for an elector rather than a candidate. How do write in candidates get allocated to those electors?
As far as write-in candidates go, at least in Florida, one must pre-qualify to mount a write-in campaign. They then submit their list of electors. FS 103.022
Regarding substitute candidates, " If the name of the new nominee is submitted after the certification of results of the preceding primary election, however, the ballots shall not be changed and the former party nominee’s name will appear on the ballot. Any ballots cast for the former party nominee will be counted for the person designated by the political party to replace the former party nominee." FS 100.111(3)(a).
Each State sets the rules for how the Presidential Electors shall function and the Supreme Court has ruled that "faithless elector" laws are Constitutional. I cannot find such a statute for Florida but it seems logical that if a presidential candidate has withdrawn and was replaced by the party, that the electors are essentially unbound at that point. But each state would have its own rules.