I guess it mostly depends on how bad your technique is. You do a power/speed event, so you need to be able to produce a large amount of force, which you train for by lifting. If your technique isnt terrible (and I predict its not if you can lift 140ishkgs), then I wouldnt think you have much to worry about. Like a previous poster said, we are not Olympic lifters.
Far too often in the gym I see people obsessed with correct lifting technique over weight lifted. These athletes are normally the slower ones.
Also, it depends on how much less weight you lift. If your 1RM drops by say 10kgs, I would say improving your technique might help, particularly in the transfer to technique at 100% LJ take-off (as you mentioned in your earlier posts). If you are lifting like 50kgs less, clearly this isnt going to be helpful!