All i see is a thing that says chain speed not anything there about supports on the coaster
You dug up an ancient thread talking about the alpha
EDIT: Corrected icon discriptions
Nowadays, when you have a piece of track selected, it has 2 pages, one with a clipboar icon (to the left, by default the one you're looking at) and the other with a 3 dots and 3 lines icon (to the right). Track supports are on the clipboard tab. They're a checkbox. The other tab has different stuff depending on what type of track you have selected. For just regular track, you can set the banking offset and turn a catwalk on or off. If you have a lift, launcher, or horizontal wheel selected, you can adjust its speed. If you have a brake selected, you can set how much and how fast it will slow the coaster, and whether or not it has a catwalk.