How to tell if btrfs subvolumes are actually compressed or not

I have mounted Btrfs subvolumes (including /home) with the compress=no option in /etc/fstab. However, when I run btrfs inspect-internal dump-super -a (both, on the running system, as well as on a live boot and mounting with compress=no), it shows COMPRESS_ZSTD in incompat_flags. So, are the subvolumes being used without compression, or with compression? Fedora 34 Workstation (GNOME), fresh install. This seems to default to zstd for at least the /home subvolume, which was not the case earlier, but is compression actually enabled despite being mounted with compress=no, as shown by inspect-internal? The partition containing the subvolumes is LUKS2-encrypted.