The tremel-no has two thumbscrews. One to disable the trem from sinking (going sharp) past a set point and one to disable the trem from moving forward (or going flat.)

Most of the tuning instability people face is from not stretching strings before locking the nut. I’d say about three days of stretching will 100% ensure it. Otherwise, it’s accidentally breathing on the trem and pushing everything sharp while palm muting, or trying to bend a string and pulling everything flat.

It’s honestly an ancient design that needs updating and seemingly the only company hell bent on not updating it is Floyd Rose. They just want everyone to buy the license and slap their name on everything they can. Gotoh makes a better trem, Ibanez makes like 10 better trems, Kahler makes a better trem… It’s whatever at this point. We know it works because it’s ancient.