Meir:
Nice supply,
I do understand your relay concept
I have the EFL-3 in a box and never put it on the car. There was no need since my rear DEPO light have 1156 bulbs for turn signal keeping the load status quo..
I did read an article about a 914 owner that purchased a LED relay and had to reverse engineer it make it work.. Might fit your situation..
Porsche 914 EV Conversion: Installing LED Lights and Fixing the LED Flasher
good luck..
T