So I was looking at one of my Buss electronic signal flasher units #234 24v 3blade (X-P-L) and a pattern appeared. They're the same!!! Yes the 3 blades are an exact match to a common 5 prong relay minus the 2 additional prongs. So why not hard wire a standard socket relay, cut off the 2 unused wires and never have to worry about the wires being hooked up to the right blade again.
Standard relay to the Left, Signal flasher to the right.

Standard automitive 5 pin Relay Socket

So I know this can't be an original idea? Don't know if it will work with a 4 prong analog signal flasher, don't have one in front of me at this moment.
Miles