It appears to be a typo that boards/include/boards/hellbender_0001.h is selecting the RP2350 VARIANT
by defining
The other board files ( even the likely associated src/boards/include/boards/hellbender_2350A_devboard.h ) seem to use
to indicate that "the current board has an RP2350 in an A (30 GPIO) package"
while the following is used to select the 48 pin RP2350B
Perhaps @CBJamo can comment