EAB Extended Format L1 .glyph is 11 times bigger than legacy L1 .raw?

[rmand]

Converting just the numeral characters (0-9) of a .ttf in rather large font sizes (within limits since if the pixel width goes over 255 you get: File "fnt_cvt.py", line 929, in run UnboundLocalError: local variable 'xf' referenced before assignment).

Choosing the legacy format results in the .raw file of about 40KB for the 10 chars.

However, if I chose extended format, L1 option for the same 10 chars is 460KB and with ASTC (auto) is 640KB.

Am I doing something wrong?