Giving fighters a free pass to interdict caps but then just be able to sit around and not take any damage is just stupid. I'm sorry but it will just make people even saltier than they are now. Maybe a not-quite-insta on stuff like Mortars and stuff but the second you make fighter invulnerable to caps is the second you open the door to a fighter just CD-spamming a cruiser so that a dread can just cruise up and throttle it point blank.
Honestly, it'd make things worse than buttcloaking.
Power does not corrupt. Fear corrupts... perhaps the fear of a loss of power.