Do you have a font file that has many comments within the first 10 lines that needs this modification in order to work? I've not ever run across a BDF font that had this issue. If you have one in mind please post a link here so it can be used for testing.

I tested this change using: https://github.com/adafruit/Adafruit_CircuitPython_Bitmap_Font/blob/main/examples/bitmap_font_label_simpletest.py
on:

Adafruit CircuitPython 7.1.0-beta.0 on 2021-11-12; Adafruit PyPortal with samd51j20
Board ID:pyportal

Run the modified version from this per is raising an exception in that environment for me:

code.py output:
Traceback (most recent call last):
  File "code.py", line 24, in <module>
  File "/lib/adafruit_bitmap_font/bitmap_font.py", line 41, in load_font
  File "/lib/adafruit_bitmap_font/bdf.py", line 46, in __init__
  File "/lib/adafruit_bitmap_font/bdf.py", line 110, in _verify_bounding_box
Exception: Source file does not have the FOUNTBONDINGBOX parameter

It's odd because my font definitely does have the FOUNTBONDINGBOX line. The same font works successfully with the current release of this library.

I think possibly there is some logic error with the way this new while loop is interacting with the containing for loop.

@slyons did you do any testing on a CircuitPython device? Are you able to try running this example and see if you can work through what is causing the error?

Closing this for now. We can re-open or make new PR in the future if needed.