Quite riight too.
De Layens is BIG on leaving combs of capped honey in the hive for winter use. He's quite specific about when to use the Fusay feeder - for early spring build-up, and presumably for later-on if needed (although he doesn't actually say that).
He goes into a lot of detail about some years in France being very productive, some years producing nothing, and even some where feeding all year long becomes necessary. His philosophy revolves around only making increase during good years, and accepting that bad years mean 'no expansion' - in that way his apiaries survived when others (who continued to perform splits under adverse conditions) failed.

That approach would hardly suit today's commercial producers of nucs and queens, but that was very much his approach as a naturalist.

Incidentally, I've discovered that towards the end of his life De Layens stopped using artificial feeders altogether, so when feeding was needed, he simply poured syrup directly into empty combs. I've tried that myself - it's messy, it ain't easy to do, and they don't get very much syrup that way.