Good news is that there is work on making the i_version field available via statx in Linux: https://lore.kernel.org/linux-nfs/20220826214703.134870-1-jlayton@ke

Good news is that there is work on making the i_version field available via statx in Linux: https://lore.kernel.org/linux-nfs/20220826214703.134870-1-jlayton@kernel.org/T/ https://lore.kernel.org/linux-nfs/20220826214703.134870-1-jl... So we might have a reliable mtime alternative in Linux soon in 2022.