Could I maybe make a suggestion?
I know there are a few people who will agree with me that the main problem here isn't who calls CAS in. The root problem is when CAS isn't needing to be called in, it destroys everything; and when it needs to be called in, it is either doing nothing or destroying everything.
My suggestion, and I know of a few voices who will back me up, is to remove the fixed-wing CAS all together. Now I'm not saying we should remove fixed wing AA, we can have two of them instead of one and allow more enemy aircraft to appear more often. To compensate for the lost fixed-wing CAS, I believe it will be more effective to replace it with a Littlebird/Hellcat/Orca light CAS. This then removes the trouble of CAS destroying everything before tanks can get there, it allows the AAA in missions to be a threat that pilots have to be weary of, adding a little more challenge; and gives the tanks a proper position in the server, to destroy the other tanks. I'll leave it up to the admins if they want to remove the rules for calling it in or not, but I believe having the light CAS be given free reign to engage (so long as it's not friendlies) will allow it to support the infantry effectively and swiftly. However, this will need to be watched, and players that TK too often in the CAS helos will probably have to be temporarily blacklisted from that role (or just a general TK ban, whatever is easier).
I'm interested to hear your thoughts on this.