Could you give a use-case scenario where you would like to implement such a custom field URL for the users? This would help us understand your requirement better.
Our custom url field has the display text = "Access Your Benefits". The url value is really long for example: http://google.com/blah/blah/moreblah/memberguide.pdf. We would like the text of the field show "Click here" instead of the long url to the pdf. So the field would display as following:
Access Your Benefits: Click Here
Thanks for the details.
I've raised it as a feature request for our Engineering team to review. Unfortunately, we don't have an ETA at the moment but we will keep you posted of the updates when they take it up.