Personal Experience: Not Good!
I tried this twice.
Once with the Cowardly Dude and a lavender plakat (RIP)
The Cowardly Dude did not fare well at all, and I don't think that the nasty plakat was all that at peace with being able to see the stranger next door, either.
The other was with my Blue DevilFish and a plakat that was unfortunately mislabeled as a female wild type. He jumped the glass, and BDF smashed him. And that was when I was finally able to see that, lo, he had no egg spot. *sigh*
So, anyway, that quaint, space-saving idea has popped. All the boys must live alone. Although, I am toying with the idea of a sorority... We'll see how that crazy train plays out in my head...