Bug: Custom action groups available when they shouldn't be

[BTAxis]

This is a long-standing bug that has been around since I've been playing KSP (1.6 at least). In career mode, custom action groups are supposed to be unlocked at level 3 of the VAB/SPH, where level 2 only unlocks the standard actions. However, at level 2, as soon as you select any part with the action group editor open, the custom action groups are added to the list and you can use them anyway.