Disk (with UTFGrids) to mbtiles

I added the possibility of making a MBTiles containing UTFGrid (with ".grid.json" extension) files from files on the disk. To check the result, I tried to upload the MBTiles produced (with TileMill and after conversion MBTiles -> files -> MBTiles) on mapbox.com.

Do I have to write something in "CHANGE.txt"? It does not seem to be used anymore.
Do I have to count the UTFGrid produced and display the result as it is made for the tiles?