CH Throttle - Ch Figher Stick + 2 column controler assignment - FYI to avoid my mistake

Do not understand the need for the double input approach for FS 2020. Discovered a self induced error that caused all planes to be unflyable. At the start {August} I assigned the “Mixture Control” to both columns and totally forgot about it until it started causing the mixture know to plunge in and out continuously causing the engine to stop. The assignment on the throttle was to a switch and the assignment on the stick was to a roller. It was the mis-positioned throttle roller on the stick that caused the pulsating mixture know. I had changed its position while calibrating the stick which after over a month of no issues due to the double assignment made all planes unflyable. Fiddled till I found the fix.