Just download OnePlus Tool and put No Navigation bar button in the quick setting and done. No need to do that much stuff to get rid of a nav bar.
I have the same problem as well. I tried installing the older version of the jOne Plus as suggested in Open beta discussion thread but still it didn't work.
This is on stock OOS 4.7.6, functional but not as good as a completely gone navbar, it doesn't disappear on the homescreen which is a problemIf you are on Oreo Beta 2, it has a Hide the navigation option in the Buttons section.
Once enabled, it then gives you a message to swipe up from the bottom to get it to appear. Works like a charm. I'm using Apex, but it appears on the Home page always.
As soon as you open an app, it vanishes, swipe up to get it back. Gesture nav would be good as well if it is true they are working on it.
This is on stock OOS 4.7.6, functional but not as good as a completely gone navbar, it doesn't disappear on the homescreen which is a problem
Codename Phoenix has a toggle in its custom settings that doesn't, using it right nowAnybody had luck with hiding Navbar completely in Oreo Beta. Here us an interesting link: https://forum.xda-developers.com/pixel-xl/themes/mod-navbar-gone-root-t3704916 If some dev can look and make one for 5T that wouldbe awesome.
su -c settings put system buttons_show_on_screen_navkeys 0
su -c settings put system buttons_show_on_screen_navkeys 1
adb shell settings put system buttons_show_on_screen_navkeys 0
adb shell settings put system buttons_show_on_screen_navkeys 1