Hiding a formula URL button with a formula

I have an application where when a record is set to "inactive" with by clicking a checkbox, permissions to modify the record are dynamically changed to prevent a user from modifying or deleting the record. I set up a custom rule on a role which works very well for this. The problem is that the records have formula-URL button fields that are not disabled when the record permissions are disabled. In other words, the buttons still work even though the record cannot be edited or deleted. This isn't intuitive, as some of the buttons add child records.

I looked at setting field level permissions for the formula-URL fields, but custom field-level rules are limited to three static choices from a drop-down. They are not formulaic like at the record level. So I'm not clear how to approach this.

Any suggestions?

Thank you.

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Paul Streit
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