yes, I have noticed this too!
parameter values of modifiers can indeed be tweened but not ticking the off on.
found this trying flashing lights, 0% to n% what ever can indeed be but not off on.
The way to get a gradual on/off for lights is not to check the visibility option and try to use a tweener, but to use the slider for the light’s brightness, and then setting your tweener. Tweening for absolute on/off type functions is limited as mentioned above by Holly and 3Dage.
lol! EP, just said that 0% to n% brightness was what I was refering to.
I said n% because I actually do not know offhand how bright they go, those parameter sliders can mostly have even bigger numbers entered in manually, I have oscillated stuff 100’s of time instead of 20 for example.