Originally Posted by
dddd
You're right about the XT- and perhaps Deore-level thumb shifters, even the 6s version had 7 solid detents.
But I don't think there are any other examples of "extra-click" SIS shifters, especially among road shifters.
My CX race bike has run 7s XT levers with an 8s cassette for over two decades, and I did slightly modify the spool groove diameter for better indexing with an 8s XTR cassette, and it's been race-day reliable over all of these years.
I think it's limited to thumbie and downtube levers with a friction option. The lever just sort of travels past where it should and sticks at the low derailleur stop. I'm not a big fan as it rarely works great in practice.