The trouble with that option is it deletes everything in that category. Inactive doesn’t necessarily mean unwanted. What is unwanted is all the duplicate entries for previous versions which result in slow firewall operations.
I also have a build up of duplicates in my Blocked category (e.g. ~50 for Nvidia driver components). I really don’t want to nuke everything. But that seems a common answer for GlassWire, just delete it all and start again.
The manual solution would be to list the version as a column, sort the entries in that order, and allow you to shift-select multiple entries. A better solution would be to have a preference check box on the Allow/Block button which give the option to automatically delete the old entries for the same app.