Custom slug for each product

A custom slug for each product would massively help me with two things:

1. Decrease the size of the characters in the link.

2. Better visual look.

This can be done through two ways:

1. Connect to subdomain — users can add the custom slug they like.

2. Shortened URL — can be a bit dicey since not all names will be available but nice to have.

If possible, a QR code that can be shared with users.