I just bought a couple of the small quilts from beethinking/beebuilt as spares.
When I removed the feeders in the late spring/early summer, I took off the feeder quilt and replaced it with a new solid quilt. That way the quiltbox quilt would not get propolis on it.
However, if it does, just order a large quilt from beebuilt. Remove your quilt box quilt and replace it with the new large one.
On beebuilt website, I didn’t see quilts when I scrolled through. But When I typed in quilt into the search box, they came up. Same thing with the wood shavings for the quiltbox.
I kept my feeder quilt and reused it in the fall feeding.