This is one of those things that you hear a lot of people debating about.
On the feeding box side
No chance of swallowing substrate
Easier to clean if there's any mess from the feeding
If feeding live, less places for the mouse to hide
According to some, less aggression
On the feeding in tank side
Less stress to the snake
You have the option to leave it over night(as you've done)
If feeding live, more chances for the snake to ambush
It really comes down to can snakes learn to associate certain places with Feeding Time. If they can, then obviously a feeding box is better because:
They're looking for food, so you're more likely to get a feeding response
They're not looking for food in their tank, so you're less likely to get bit
The main reason I feed in a feeding box is because my snake seems to have learned that that box means food is coming and will immeadiately go into "hunt" mode and so far has never even histated to strike and eat for me, also I could stick my fingers directly into my snakes hide and poke her in the face and she wouldn't bite me.
Now it's possible that my snake would do this anyway, but since it's worked this well for me so far, why would I want to mess with something else.
I would prefer myself for her to eat in a feeding box, I tried but she won't take the food... so how do you think I can solve that problem..? Keep on trying?