The only issues would be,
1. Will it leak?
2. How to move the airlock to the top edge of the lid where the CO2 can escape, instead of in the middle of the lid where it will be covered by liquid. (Some type of L hose would have to be rigged so the airlock stands up straight)
3. And when you go to bottle or keg, I am sure you would be stirring things up when you move it which means all that stuff that settled will be back in your keg or bottles.