Making changes to GURPS Ruleset with extensions

[YAKO SOMEDAKY]

I like to make changes using extensions, so in GURPS Ruleset I made some changes and I added a new field to manage the shield life points, but then I ask myself and if there is no shield, this field will appear in the CT of the player, so I put an extra option in the options to manage the hit points of the shell
Detailed: Shows the points as number
Status: Shows some "name"
Off: Shows nothing


But when I had the option turned off, I would like nothing to appear in the CT of the character, nor the Label .. and if someone can give me a tip, help me I am very grateful ;;;
I know I need to improve and in time I will ...
If you want I share the same and to find the changes just search for "shield"
And I need transform the shield hitpoint in attribute to link the info of the item to the CT