iOS UX : Switching between custom keyboards

A friend of mine just released a custom keyboard called Muggie. This keyboard offers a great method to share recorded GIF animations, quickly. 

While playing with Muggie and attempting to switch to another keyboard, trouble arose. Switching between custom keyboards was confusing. When you have more than two it is quite laborious to get from one keyboard to another intended one.

I wondered if there was a better method to switch between keyboards.

Note : Got a great comment about whether the swipe would result in keys being tapped. Would this solution not work when implemented on the phone?

Before posting the idea, I played around with 'swipe' based keyboards and also the Apple default one. I was able to simulate a hard/force swipe from the edge that didn't result in keys being tapped. I tested this quite a bit with satisfactory results.

However, Apple would have to detect a tap that originated from the right or left edge of the keyboard. It would then have to continue at lease 1/3 of the distance across the screen. Only then would the user get the hint of the other keyboard coming in from the side to overtake the existing one.