You are absolutely correct. The legislators could decide on their own volition to send electors who would vote for a candidate other than the one who, at least, by fraudulent counting, “won.” However, this would take a lot more than a stiffened spine ! It would likely take toxic doses of viagra and testosterone combined. They might be a little more inclined to send Trump electors if the Supremes made a statement about the massive fraud which was enough for them to void the votes of the entire state.
I agree with that.
And I don't see a rule where the legislatures are prohibited from talking to one another. They could collectively set the Electoral College votes so that neither Trump nor Biden win, which would then throw the contest into the House. This would give the legislatures a little bit of a cushion from the firebombing that would ensue.