https://www.romhacking.net/hacks/7119/

Z2 improved on Z1 in the ways it handled penalties for Cyber Elf upgrades. Rather than subtracting 10p permanently from your score, it would subtract either 5p or 10p from your current mission, followed by a permanent 2p or 5p reduction. One-time use Cyber Elves subtracted 1p from your current mission. Like the MMZ1 Revisited Patch, this has been overhauled by the Elf Penalty patch. Permanent upgrades do not subtract anything from either your current mission or future missions. One-time use Elves will subtract 5p from the current mission. Additionally the damage penalty has been changed from 1p per 5 damage to MMZ3’s more forgiving 1p per 6 damage.