PSP Font Auto-Generate from TTF

[chrome99001]

So I've been trying to create custom fonts to replace the fonts within the Final Fantasy 3 ISO (Using the DS font, as it looks so much better). But everytime I use the ISO with replaced font, PPSSPP would just crash. So I decided to make a bmp dump of the replaced font along with the original font to make a comparison. Seems like the generated font is bigger in height than the original.
Also, there are actually 3 pgf files within the ISO, "font_8.pgf", "font_12.pgf" & "font_14.pgf".
Anyone has ideas on how to fix the issue? I've been Googling around and can't seem to find much info on pgf editing.