For the first 35 years of its running, the Adirondack 90 mile canoe race required a PFD to be on board as a legal requirement, but actually wearing it was optional unless the race director required it be worn due to weather conditions. Now that the NFCT has taken over running the event, insurance requires 100% wearing of a PFD. I think most every other race or official event I have seen now has the same requirement.
For many years I have used a Kokotat Orbit, which has two pockets to hold the minimal on-person mandatory survival gear required on Yukon races. Closer to home in normally calmer waters, many of us have gone to wearing inflatables. The NRS inflatable in particular has found its way to my crew due to a substantial discount by one of my paddling partners being a NRS employee.