Auto-hide Nav bar & hide tab bar when only 1 tab w/FF 57

[cjtcjtcjt]

I have to admit & appreciate FF gave us ample warning of the problems migrating Ad-on to FF 57.
No being a programmer, I didn't anticipate the magnitude of the task and quietly waited for upgrades for my favorite "Auto-hide Nav bar" & "Hide Tab bar w/1Tab" Ad-on.
Apparently it seems a little more complicated .

So, rather than messing around after upgrading I'd d prefer taking care of it BEFORE.

Is there someone kind enough and be able to point me the right direction?
- Wait for upgrades (I've heard a lot of developers are throwing the towel )?
- Any replacement or equivalent Ad-on compatible w/FF 57? So far, no luck
- Last time with a similar problem when upgrading to ff 52, a wonderful angel wrote a script for me to tinker with the obsolete libraries.
Could there be another miracle again????

For the Tab bar, if the "Hide" function is too complicated, how about (in fact how to) get completely rid of it. Easier?? ... acceptable to me.
(I use the open new Tab in a new window function). This bar doesn't make any sense to me using multi-screens.

Any help would be gREATLY appreciated.

Tia & bst rgds, Ch.