I've seen setup made with both Besta & STUVA mixed together to fit some deeper statues like Hulk and others.I think so but closest IKEA is four hours away for me to verify. Looking at website the depth and color as you mentioned is the difference but wasn’t sure if the shelves and doors worked.
Like this one from aslan_gfx
You can see more of his:
https://www.sideshowcollectors.com/forums/showthread.php?t=55290&p=6579762&viewfull=1#post6579762