In the pic, it may be possible that by pushing the shifter inboard the curve of the handlebar angles the trigger lever toward the grip. Kinda hard to tell.

If you move the grips outboard a few millimeters = Does it fix the issue? There's the solution.

Sorry - cannot answer q's about trigger lengths between other products.
edit: none will be 28 miles long

re-edit: Horns, or bells, or lights, or mirrors or computers that get in the way of comfortable hand positioning and shifting on the bicycle should be moved. There are too many options available in the market to sacrifice comfort and/or handling.