How can customers access specific GitHub repositories for updates?

Hello there, hope you’re doing well !

As many know by now, Shopify has enabled a connected installation of its theme to collaborate between developers with Github.

I would have liked to hijack this system and know if it was possible (if so how?) :
I’m the developer seller of the Phantom Theme.
We offer 3 different packs. So I created a GitHub organization with a repository for each pack.
I would have liked to know if it was possible to allow our customers to connect to the repositories for the right pack only, and only having the rights to read the one without being able to write on it. This way, we could deploy our updates easily to all our customers, per pack, and without any hitch.

If you think you have a lead to follow, I will be happy to discuss it with you, why not even help on one of your projects in exchange!

Best regards,