Morning Matt,
The famous thing to have a T/S running backwards is a to far advanced
ignition and to that end I believe the German Messerschmitte 3 wheeler had 2 sets of points the second set advanced so when you needed reverse you switched to that set and then go through the gears up to it’s max if you were so inclined. I recon that’s why it had a bubble canopy so you had a good view while you are going a blast in reverse.
Safe riding Matt take care Alan.