We have the options in Game Master to switch tabs with the keys Q and E. But it would also be helpful if one could tab through certain modals.

E.g when opening the scenario properties the user cannot tab into the form, or through it.
The keyboard input only allows the functions to switch between the different available tabs (factions, game, time and date, weather).
It would make sense to allow tabbing in this modal and the respective submenus of each tab.
A keyboard user typically uses the tab key to navigate through interactive elements.
When an item is tabbed to, it has a keyboard "focus" and can be activated or manipulated with the keyboard.
The focus indicators should be provided automatically, just like when hovering a mouse over an element.
Shift + tab should also allow to navigate backwards in the modal / menu.