Before you accuse me of heresy, there is a little justification.....
Following the usual series of modifications, big valves, ported ports, hi comp slipper piston, skimmed head etc., preventing clutch slip necessitated extra plates, stronger springs and even a lovely alloy basket. Clutch lever, although "firm" was do able, and good fun was had by all.
Then came the surgery on my left thumb ..........
An hour of riding resulted in a week or more of discomfort.
Then I found this
https://www.ebay.com/itm/251578454285 At only $50 I figured it was worth a punt. The damn thing fitted straight on with no modifications, it was if it was designed for a unit single, even the rubber sleeve was in the right place. The action is a revelation, and an hour of riding only results in a day or so of pain, back to being worth it!