Rclone mount on android -- almost there, but permissions bug?

You can try to disable selinux especially since you wanted to set weird executable permission for your files.
I doubt that will help.

Where did you put the path for rclone and fusermount then? If you put it inside the path of termux that would probably the reason other apps can’t see it too and it probably is not persistent

I suggest you take different approach. When you use mounting with namespace enabled your apps needs superuser elevated privilege to read that mount point. I think samba mounts on shield doesn’t use that. So try to disable namespace.
Did you try to set the same uid, guid in your rclone mount the same as the one in your samba mount?
I think your best bet is to make your rclone mount have similar properties like your samba mount.

Instead of fx,use a proper file manager like solid Explorer which available for TV ui.
My old Sony z3 phone has a feature to mount remote file system so it’s not dead end.
But if you only get it work for superuser I think you have wrong uid,guid and umask setting, or selinux got in your way.

I suggest you to troubleshoot it like this logic. First you want to make sure you mount with the simplest option.what matter here is that it’s persistent with correct uid,guid and correct permission due to restrictive nature of selinux.
Since you seem to have working fusermount you can try to mount simple stuff that’s already proven to work on shield TV.
For example you should try to mount your samba or sdcardfs or sshfs. Once you get that then you play with the correct uid guid. Then you can use similar setting for your rclone mount.
Anyway there are old posts for old android of people rooting tablets and mounting samba, sshfs etc in their phone and tablet.
I believe the concept is still the same, so try to use the same setting for rclone mount that would result in same way of mounting.

I don’t want to root now for several reasons:

Current 7.2.2 has mount related bug, so even if rclone and fusermount works there’s possibility is still not working because of this. In this firmware samba connection sometimes reports successful etc and things seem to be mounted but you can’t actually access the data.it seems to be regression bug.

I have A LOT of movies and TV shows in nvidia plex server, probably around 70,000-80,000 of movies+episodes metadata that I will lose if I root my shield. Stupid plex let you back up the data but doesn’t give any reliable means to restore the data. And around 30,000 of those metadata is irreplaceable because it’s not on tvdb ( because they are European, Chinese, Korean and Japanese TV) so it’s manual work literally hundreds of man hour spent editing metadata.

Some app like BBC iplayer TV, itv hub, and some Korean and Japanese local TV app won’t work with rooted device. Gyao and abema etc.

Lastly the benefit of rooting is small at this point. I would save only around 10watt per hour by eliminating my nas. And each time I click on “play“ until I receive first image frame is going to be only 3-5 seconds faster. Using nas with rclone, with nvidia plex server it takes around 6-10 seconds to play a movie . Using plex server+rclone mount in the same device it will be 3-5 seconds faster in my case.
I tested this. I have 2 identical plex servers one on the nas and another one on the shield.

And also all my game settings and data on shield.

I probably wait until another major firmware update before I try to root my shield.