Use case or problem
Now that Obsidian supports internal links in properties and allows masking them, it seems strange that external links cannot be masked in properties. External links work as expected and act as links (e.g., https://example.com), but the same is not true for masked links (e.g., [Example](https://example.com)).
Proposed solution
The simplest solution would be to support the [link text](link) syntax in properties. If this wouldn’t be ideal—it would be breaking for anyone expecting plain text, but the same was true for internal links so I don’t think it’s too problematic—perhaps a more general solution would be to add a “Markdown” type for fields that behaves almost equivalently to the “Text” type, but renders markdown. I don’t think I would personally find a use for it other than masked links, though.