Thanks echo8hink,
Your comment suggested to me a work-around:
Change the tab color of every second tab.
The alternating color pattern will make the tab boundary easier to see.
My tab names are only 3 characters long and I have over 50 of them on this one spreadsheet.
This solution is not ideal. There is a border on the Column/Row headers, but until they add that feature ‘back’ on the tabs, It will do ‘for now’.
Thanks