Be sure to check your state's rules for write-in votes before that. In some states, a vote for a write-in that has not been pre-registered will invalidate an entire ballot, thus voiding your votes for Republicans down-ticket.
If you can get Thompson/Hunter registered as an official write-in selection, feel free to do so. Depending upon the state, it may not even cost anything. But whatever you be sure your ballot counts for the down-ticket races.
Point well taken. :-) I’ve got a friend who works for the board of elections here in my state, and I’ve got a query in with her now. :-)