Thanks, but I have an idea. Use GBOX and put the starting coordinates at the sprite u,v and the end coordinates at the sprite's w,h. That will have to be adjusted when using SPHOME but that might work?
Try this function. Make sure you actually have defined the hitbox with SPCOL first.
DEF SHOW_HITBOX ID%, COL%
VAR X#,Y#,W#,H#,XX#,YY#,S%,SX#=1,SY%=#
SPOFS ID% OUT XX#,YY#
SPCOL ID% OUT X#,Y#,W#,H#,S%
IF S% THEN SPSCALE ID% OUT SX#,SY#
GBOX XX#+X#*SX#,YY#+Y#*SY#,XX#+(X#*SX#+W#*SX#-1),YY#+(Y#*SY#+H#*SY#-1),COL%
END
Usage: SHOW_HITBOX spriteID, color