Great work. Time to find the same data on remaster version. I will try to do that soon.
EDIT: I confirmed this. Data is pretty easy to read and edit if you arrange it to 8 columns and do the hex to dec conversion first. In remastered version this data is in el_mask.bin file and the 2nd file in the exdat.dat file. (Why the dublicates...?)
Format is following:
The line number is the star level. (0-99)
The column number is the growth table index. (0 for Serge and pals, 1 for Dragoons, etc.)
For data xy in decimal format: x is the x-coordinate in the grid (element level -1) and y is the y-coordinate in the grid (6 is the middle line while 2-5 are above it and 6-9 below it. 0-1 aren't used but may work?). 255 (FF) is no new grid slot at that level.
Grid slots 06, 16 and 26 are automatically open at start, though they can be disabled for any character in character's own grid data.