It may not confuse the experienced SR player, but at least one member of my group isn't sure how to interpret "natural maximum" in reference to cyberlimbs, so I thought I'd post it here.
If a human character has a natural Agility of 4, Muscle Toner 1 (raising Agility to 5), and wants to buy a cyberarm with a higher agility, which of these two scenarios is correct?
Scenario #1
The character buys the base cyberarm (Agl 3), increases it to the character's natural level of 4 (Customization +1), then increases it further to 7 (Enhancement +3).
Scenario #2
The character buys the base cyberarm (Agl 3), increases it to the natural maximum of 6 (Customization +3), then increases it further to 9 (Enhancement +3).
Scenario #2 seems to be correct (even though it's more subject to abuse than Scenario #1). The confusion comes with people thinking the "natural maximum" is referring to their current stat before cyberware modifications, instead of the maximum for the metatype.