Rated 5 out of 5 stars
Ok, follow-up review...
The developer provided a fix for the problem I reported with AutoShow/Hise not working properly when all toolbars are hidden, but I then discovered that there was a conflict with another necessary extension I use - Tree Style Tab. When this extension is also installed and Tabs are displayed on the left side (and probably the right side), if you hide all toolbars, the AutoShow/Hide functionality breaks.
I have reported this to the developer, so hopefully he will be able to find a fix so I can hide the (empty) Navigation toolbar.