In some blueprints i’m using a urlField to create a dedicated sign up button in the frontend. now the question came up from the client why its not possible to use a mailto: url there. Personally i like the idea of having a urlField which also validates mailto: input (optionally) as i think this is a common use case and better than falling back to simple textfield without validation.
i think you could create an issue or idea issue to accept mailto: as an valid url schema not just http(s)://. this way your input would be a valid url. https://schema.org/email
but maybe thats not a good idea since then a lot of custom schemas like skype, slack etc might be requested. but probably the devs will respond to that.
yes, i thought about discussing it here first. maybe there are intentions behind limiting it to http(s).
my proposal to the validation it would be: make it as general as possible by following the definition -> https://en.wikipedia.org/wiki/Uniform_Resource_Identifier#Definition
you can still add an optional list in the blueprint which acts as a whitelist to the schema