This mod makes glass break when it hits the floor in item form, I know, super useful, anyways here's how to add to it
The path for the tags are: data/glassmod/tags/items/glass.json
by default the mod comes with most the vanilla glass items in the glass json
here's the code, an example of a mod-compatible Override (CC0)
https://gist.github.com/Devan-Kerman/f2c5ef6f00ebe6f2225f426387085aa3