noatime/nodiratime/relatime mount flags are not honored by fuse. We can observe GETATTR request overhead for read-only workloads, as fuse kernel component unconditionally invalidates attributes upon read -- overriding its own mechanism for relaxing GETTATTR flow, the attribute timeout -- to force retrieval of up-to-date atimes. To relax this user's attempt to "unsusbcribe" of atime updates via said mount flags should be honored.
Miklos' recent work on trimming GETATTR requestst on read -- see upstream commits at https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git/log/?h=fuse-update-4.20, this list of changes: fuse: only invalidate atime in direct read fuse: don't need GETATTR after every READ fuse: allow fine grained attr cache invaldation or Bug 1650538 for the RHEL 8 version -- makes this request unneeded, as with this optimization there is no need to make special allowances for noatime/nodiratime/relatime mount modes.