it will have whatever rights are granted to public, we can only surmise that is all the app requires.

It has been granted view any definition so will be able to see metadata.

It is best to keep the permissions at the most granular level anyway rather than try and find a higher level role that would give more permissions than required .

as Erland says you a likely going to have to tweak the script anyway to make it work. Creating an unnecessary schema would be a slight performance hit whenever this ID accessed a database.