Mike
As Jake noted...a CE vest makes it easier to get under the boom.... This is an advantage... The US Sailing Prescriptions (part of the RRS we must honor) require CG approved vests to comply with federal and state law.
CE vests have less buoyancy then CG vests.

Do you expect the competitors to honor the rule?
Do you expect competitors to enforce with a protest?
Do you expect the RC to protest?
Do you expect the OA to attempt to manage the issue and change the rules with the SIs?
Do you expect the OA to be smart about it and not mandate wearing a CG life vest in the SIs.. (So.. you can just have one on the boat)
Do you expect the OA's to take on responsibility by over ruling the USCG safety rule and finding a way around?
Do you expect the manufacturer to push a change in safety standards through USCG (less flotation).
Do you expect Dave and or Todd to bark at unamed individuals to fall in line with the majority in the fleet?
Do you expect clubs to embarass sailors who are not following the rules by calling them out individually but not protesting?

My view is that I can honor the rule by stuffing an orange CG vest in my hull and wear what I want... a CE vest. I count on the OA not taking away my responsiblity as a skipper by requiring a LJ at all times or worse... a CG approved LJ at all times. So... to the extent that as a PRO you don't fly the Life Jacket required flag OR put LJ requirements in the SIs... I agree... We have a work around.. It is a PIA to pull that orange POS jacket out of the hull to dry.... but I choose my poison.

US Sailing feels that as the standard bearer... they must set the example and so they require wearing CG vests at all of their named events at all times... (could be a keel boat J22 drifter and the gals are still wearing vests).

Most events ignore their lead thankfully!