The 2015+ left shifter works differently than any other previous model. It only has 3 clicks, with the first being the only one needed to drop the chain from the big ring to the little ring. The other two are just trim clicks. It requires either a frame mounted or inline cable tension adjuster to work best. I couldn't say how it might work with older FDs.

I much prefer ultrashift levers to the old ergo style. You can't buy internal repair parts, but they are less likely to have problems. The ultrashift internal mechanism is far simpler than ergo.