Just clarifying my original post. By "doesn't always work change" and "stops working", I mean that the display didn't respond to changing the tabstop with "/window -t @win NewNumber". It would eventually react to the commands after double-clicking in the window, or writing to the window with /aline /rline or or /echo, or by changing to a different editbox to continue repeating /tabtest. When the window was created using the -l switch, I wouldn't need to do any of the other things, as it would immediately change the tabstops in the display.
