• Size: 25×25
• Version: 2
• Error correction: M
• Contents: HTTP URL to a link shortening service that requests access to location data (18 characters)

As the link shortening service uses case sensitive paths, there is no simple way to move to alphanumeric encoding. Presumably, if the link shortening used only uppercase letters, the addresses would be correspondingly longer, and we would likely end up more or less where we started.

Besides, this code is at version 2 already, and version 1 codes may in some cases be harder to scan, since they lack the extra alignment pattern. Thus I conclude that there is not much opportunity to improve this QR code.