With the notable caveat that in this example, mount(2) will clear all other filesystem parameters (such as MS_NOSUID or MS_NOEXEC); fsconfig(2) will only modify the ro parameter.

MS_NOSUID and MS_NOEXEC are not filesystem parameters. They can be set per-mount, but not
per-filesystem. Here is list of all filesystem-agnostic per-superblock parameters:

https://elixir.bootlin.com/linux/v6.17-rc6/source/fs/namespace.c#L4103

Note that these SB_* constants are equal to corresponding MS_* constants.

As you can see, there is no NOSUID and NOEXEC in that list.

Also, SB_NOSUID does exist:
https://elixir.bootlin.com/linux/v6.17-rc6/source/include/linux/fs.h#L1240
.

So, it seems that "NOSUID superblock" does exist as a concept. But, thanks to
code in path_mount (provided above) user cannot (in filesystem-agnostic way)
make given superblock NOSUID.

So, from user point of view, NOSUID and NOEXEC are not filesystem parameters.

If you need some example of filesystem parameter, I suggest MS_SYNCHRONOUS,
I used it here:
https://lore.kernel.org/all/198d1f2e189.11dbac16b2998.3847935512688537521@zohomail.com/ (local)

-- 
Askar Safin