I think you're trying to be too damned legal hear. I have 27 years of service, active duty O-5 in the USCG and have worn my dinner dress with kilt to seven functions: Navy Ball, Navy Nurses Corps Ball, USMC Ball, and four USCG Balls with the Commandant in attnedance at one of them and only received praises for my attire, even from Admiral Allen the Commandant. Oh, and it wasn't even the CG Tartan!