I have been using SPPB for quite a long time now, but I find the switch to have the menu submenu's creation withing the Template Styling setting to be a huge mistake.
Needing to go to make these changes through the Template settings is very cumbersome and time consuming. Please add the previous settings to adjust submenu's through the Joomla Menu settings by adding a tab there with SPPB options. This is much more clear, logical and practical.
At the moment I find this new approach a complete failure.