The only flotation systems I've used have been Navy issue. I wore an LPU-32 the last time I qualified. The only swim stroke required or desired was the breast stroke and it is performed before you inflate. After the vest inflates you are floating, not swimming.

If you do decide to swim after you inflate the vest, partially deflate the bladders using the oral inflation tubes as DR mentioned above and swim. Inflate via the tube when it's time to float again.
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Better is the Enemy of Good Enough.
Okay, what’s your point??