I added a hacky thing where it logs which extended picture operation is used in which pics, triggered by simply opening the picture browser.
KQ1 uses 0x02 PIC_OPX_MONO0 fourteen times total, in pictures 4, 5, 12, 15, 16, 23, 24, 27, 30, 31, 35, 36, 37, and 38. No other extended ops in that game.
LB uses 0x02 PIC_OPX_MONO0 37 times total, in pictures 1 through 38 except 19.
0x03 PIC_OPX_MONO1 appears 19 times, in pictures 1, 2, 3, 5, 7, 8, 10, 11, 12, 13, 14, 17, 22, 23, 25, 26, 30, 33, and 37.
0x05 PIC_OPX_MONO3 appears 29 times, in pictures 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 17, 20, 21, 22, 23, 24, 25, 26, 28, 30, 32, 33, 34, 35, 36, and 37.
0x04 PIC_OPX_MONO2 and 0x06 PIC_OPX_MONO4 are marked as hitting in LB, but they don't seem to.
(Also, according to the code, it's 0x02 that takes 41 bytes, not 0x03.)