I like the Samus / Zero Suit Samus works now. But, I thought it would be cool if when Samus breaks her shield, there is a little blast from the armor that does a little damage and knocks sends the enemy away, then she turns into Zero Suit Samus, but the downside is your armor blew up so you don't get the armor pieces. It's essentially a get out of jail free card if you get shield broken, but forces you to use another character.
If you want to change her back, you have to use her smash taunt twice, and they are quite long, so you would have to possibly get a star ko to complete it in time. After that, the this two rings show up and go up and down samus as she is glowing (Kinda like how she would glow during transformation) and from under the brightness you would see her stand strait up facing the camera sparking with electricity kind of how when you continue in Super Metroid and she faces the camera. This leaves her open for a while just like going from Samus to Zero suit.
And as a Bonus, like in her game, she can stay idle like that as long as you want as long as you choose not to move her.