Per https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/tree/doc/RelNotes/v1.46.4.txt, after e2fsprogs upgrades to 1.46.4, the defaults for mke2fs now call for 256 byte inodes for all file systems (with the exception of file systems for the GNU Hurd, which only supports 128 byte inodes) and use "lvcreate -L 50 -n lv_test1 vg_test && mke2fs /dev/vg_test/lv_test1" and then continue to check the partiontion as below.(use lvm2 2.03.11 for the test)
# df -h | grep dev/mapper/vg_test-lv_test1
/dev/mapper/vg_test-lv_test1   48M   14K   46M   1% /mnt/lv-test

Though claim 50M as above, but it turns out to be only 48M.

Thanks,