How to enable masking of PII in logs that's URL encoded

In Cloudwatch Logs, we've enabled masking of email addresses via arn:aws:dataprotection::aws:data-identifier/EmailAddress

However, we're still seeing emails in the code if they have been URL-encoded. e.g. email=some-user%40gmail.com

How do I enable the masking of these values? Please note that we are unable to URL decode the value since it's not under our control.

If this is not supported, I think it's either a defect or a feature request.

Thank you.