I just finished my setup and have put in a t-track waste board. In a space about 35" wide I have seven tracks and 6 MDF inserts each about 5" wide.
I got my t-tracks from Lee Valley. They are 36" long, 3/4" wide and 3/8 " high.
I filled the spaces with 3/4" MDF that is actually a bit thicker than 3/4". As a result, I have just over 3/8" clearance from the top of the MDF to the t-track.
I connect the boards to the base plywood with 1/4" x 1 3/4" bolts into t-nuts in the bottom of the base. I used a 3/4" Forstner bit on the top to make space for the bold head and washer. I drilled it a bit more than 1/2" into the MDF and when the bolts are tightened I have 3/8" clearance there as well.
I see at least two major benefits to this system (which I stole from “CNCnutz” on Youtube). First, Each of the MDF inserts can be changed out as required without replacing the entire wast board. Second,since the Long Mill is not attached to the waste board I don’t have to detach it to replace/repair the waste board.
The attached picture shows the current setup. Hope this helps.
Now I have to figure out how to program the sucker.
ron