I tested this with the following example: https://imgur.com/a/hTsvV3Z

> 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-.:

This is wrong: alphanumeric has 45 characters, not 44. It’s missing the second last character, /.

(The slash is important because it makes alphanumeric-mode URLs possible: you can write HTTPS://EXAMPLE.COM/PATH which will be parsed to https://example.com/PATH. No query string due to no ?&=, and your server must accept the uppercase path.)