it's been suggested that boiling for any period of time does not kill yeast.
Huh, that's a new one to me. I'm not saying it's not true, but I've never heard of that before. If that were true, then the boiling-water bath canning method would result in jars with pushed out lids and a loss of vacuum...because the yeasts produce CO2, a gas. Can you point to where you read this?