I have not been using padlocks on Lucy's Hensley's over center latches, but I have always used an extended hasp Master padlock on her coupler. I have used the same lock for eight years now. It has always been in place and rarely unlocked. About the only times that it has been unlocked was to grease the ball, which wasn't as often as it should have been. This lock has never malfunctioned or jammed.
SuEllyn & Brian McCabe
WBCCI #3628 -- AIR #14872 -- TAC #FL-7
2015 FC 25' FB (Lucy) with HAHA
2005 Suburban 2500 Quadrasteer (Olivia) & 2011 Silverado 3500 (Fred) with Outfitter Truck Camper (Ethel)