Does not tolerate `+` in protocol

[rotu]

What is the issue with the URL Pattern Standard?

URLPattern doesn't tolerate + in protocol. The polyfill gives this error:

new URLPattern("web+foo://example.com/baz")

TypeError: Failed to construct 'URLPattern': Unexpected OTHER_MODIFIER at 3, expected END

This is especially a problem since the web+ prefix is mandatory when registering schemes.