So, this dude comes into the shop complaining his boot has given him extreme discomfort over the day. He informs the bootfitter that it was his first time wearing them this season and that he had kept them buckled all summer (which our shop suggests).
Upon pulling out the liner, we discover 3 baby mouse corpses. Mama mouse had made a home of his liner but didn't make it along for the ski trip.
He bought new liners that night.
So unless they are sealed, I'd say pull the liner and buckle.