So thinking about this, since what you want (ShowInEditor) is practicaly only applicable in the Script Control Tasks (Execute, Get, Set etc), creating a virtual method ShowInEditor is a bit overkill in my opinion. Here are 2 solutions:
1. Interface way
Create an interface like IReflectionTask with one void method ‘ShowInEditor’.
Implement that interface in all Script Control tasks and it’s method ShowInEditor (like you did)
In Node.cs line #638 where the double click is handled, add this extra check: