Did you know that it is possible to disable the softkeys and enable Navigation bar like the one present in Nexus tablets? This has to be done in such a way that you must enable navigation bar first and then disable the Samsung softkeys.
This method also requires you to have root on Tab S tablet and file manager with root manager. I recommend using Solid Explorer.
To Enable NavBar:
In root file manager:
open "/system/build.prop"
add this line at the bottom of the file
qemu.hw.mainkeys=0
Reboot to ensure the Navbar is enabled before moving on
To Disable Softkeys:
In root file manager:
open "system/usr/keylaout/Generic.kl"
The Generic.kl contains all the key mapping. Search for the following keys (158 and 254) and comment them out with a # symbol. They will be looking like this:
# key 158 BACK # key 254 APP_SWITCH
Then using the solid explorer, open open "system/usr/keylaout/gpio-keys.kl". Commet the 172 line with # symbol. It should be looking like this.
# key 172 HOME WAKE
Now let us disable the softkey backlight. To do this, go Settings > Display > Advanced (section) > Touch key light duration > Always off