I have no idea what Homasote is.
Im on my 6th plane now and have found 1/2" gyp board, (drywall) placed on top of my building board, a 4'x8' plywood table with a 3'x8' solid core maple door, works fantastic.
T-pins go in and hold very well and, its heavy enough to lie flat without having to attatch the drywall with screws ect..
Its extremely cheap, about $6 and available immediately within a few miles of nearly every home.
Thats my take, its all I think Ill ever need, however, like I said, Im not familiar with the Homasote, I typed in my zip in the above site given to see where its available and apparently, its not available in the 38305 zip.