I do not think it will help. Maggies like everything behind them to be very proportional and measured out to sing. I never did like the plants as diffusers that you see in a lot of set ups. To me they sound the best with a flat wall behind them and if you need to diffuse, the entire back wall needs to be the same material. Physical objects behind them make the panels easily located by ear and the destroys the very magic of them to disappear, my favorite part.
Maggies are very greedy for open space and air, they don't like anything around them. If you provide them with that environment I promise you that you will reach another level that will grab you emotionally. No equipment between them, nothing, give the the whole wall uninterrupted and yes keep them out like you have them.
When you hit the sweet spot it is a lot better than "they sound nice" , it will move you.
They need a lot of fiddeling to get there but its worth it.