I noticed this issue whilst testing my own addon, it actually broke something I added so I used mixins to change this. However I personally want to avoid interfering with the original mod code so I'll throw this oversight here.

I may provide my own pull request to fix this however I'd like to check if it's an oversight as opposed to being intentional before I do so.

For example this allows the command to give an Elytrian better than Chainmail armour provided they don't take it off:

Fixed in 0.7.2. :)