We have hidden away the editor type menu to switch to other editor types since it steals UI space. But you can make it visible again. Right click at the header, untick “Hide Editortype Menu”, and the menu to switch to other editor types will reappear. Be cahreful here not to kill the layouts. ALL changes at the layouts will be saved.
To make this change permanent, save the startup file. Then the editor type menu will stay visible the next time you load Bforartists.
Hope that helps
Just curious, why do you want to split the windows all the time? There is the UV layout that contains both, UV Image editor and 3D view.