Personally I think that it would be a good idea to change the Track Builder forum category icon from the blocks to an infinity sign. It represents the infinite possibilities as well as resembles the shape of a figure-8 track. It would also conform to the FontAwesome icons that they are currently using (The only difference being that instead of fa this prefix is fas because it is a FontAwesome Solid style).
I kinda like current one, it is blocks you put together to make a track. Then again, I can see how track builder symbol in game and at the forum would make sense to be same, so it is almost tie to me, but I'm thinking that keeping current one would save bit of work.
The choice is from what the forum software has. It does not have any infinite-like icon. The current one is because Track Builder <-> Building blocks
