Could the "Have the Legislatures Choose the Electors" Dodge Work?

One suggestion in the fight to decide who gets to serve the next presidential term is that state legislatures could defy (actual or alleged) election results in states where Donald Trump seems to be behind Joe Biden but is claiming fraud, and just directly appoint Republican presidential electors.

On one hand, there's nothing in the US Constitution to prevent the state legislatures from choosing presidential electors as such:

Each state shall appoint, in such manner as the Legislature thereof may direct, a number of electors, equal to the whole number of Senators and Representatives to which the State may be entitled in the Congress ...

On the other hand, that doesn't mean there aren't problems with, and obstacles to, the idea.

Let's take Pennsylvania as an example.

The first thing to remember is that in all of the states, the legislature has already "directed," via the passage of election laws, that the voters shall choose the presidential electors. It would take a change in law for the legislature to directly assume that power.

And there are two HUGE  problems with any attempt to implement such a change in law.

One is that Pennsylvania has a Democratic governor who could veto any such legislation. The Republicans do not control 2/3 of either house of the legislature such that they could override the veto.

The other is that Pennsylvania's constitution prohibits the passage of ex post facto laws. Any change in the way that electors are chosen would apply only to future elections, not to the 2020 presidential election, which has already happened.

Georgia has a Republican governor, House, and Senate, but its constitution also prohibits the passage of ex post facto laws and its election laws also assign the choosing of presidential electors to the voters.

Michigan has a Democratic governor and a Republican House and Senate without veto-proof majorities. Its laws also assign the choosing of presidential electors to the voters, not the legislature, and its constitution also forbids the passage of ex post facto laws.

Wisconsin likewise has a Democratic governor, a Republican House and Senate without veto-proof majorities, election laws assigning the choosing of presidential electors, and a constitutional prohibition on ex post facto laws.

Absent possession and use of a time machine, it doesn't look to me like that's a plausible route to a second Trump term.