Seems to me removing the extension lever is easy. Can't you just take it apart down to the lever, remove it, then replace it with an aluminum "washer" or the same thickness? I have some scrap 1/4" aluminum. I"d just cout out and drill this washer from that plate, then file and mic it down to the thickness of the lever. Reassemble and done. Yes, shortening things up would be cleaner but I would do this as a QAD (quick and dirty) approach to see if I like the concept. If it works, take it apart further, measure and draw up the pivot bolt accurately, reassemble and make a pivot bolt that washer shorter, meanwhile happily riding the QAD setup.
Ben