This is something I've been wondering lately. Whenever you change headequips, your white mage may possibly lose your target. I only macro in swift belt for utsusemi (I keep on 3x homam), to avoid making my character disappear and possibly have WHMs not be able to cure me, so I generally stick to keeping on the same headpiece for a whole fight aside from Rampart macro (testing out what Valor Coronet actually does for it after the update). If I'm tanking something where I'm positive I'll always have hate, like Voluptuous Vivian or small groups, I just keep turban on full time.
Do your linkshell whms (or yourself) just use macros with the tank in question's name that does a lot of equipment swaps, or type out the spell manually? I have one very good WHM that I can trust with just about anything (and it's not you kupo lol), but usually I forget to ask if it's an issue for the others, and I'd like some feedback on what's most comfortable for a lot of WHMs.