If you lack balance while riding English, you will likely fall off, so YES! If nothing else, it certainly won't hurt, and you'll have tried something new
Do you have someone who can lunge you? Here's a great exercise to improve you balance (in an English saddle). Don't do this until you've ridden in it a few times and have the feel for things. On the lunge-line: remove your stirrups - leathers and all. Go around a few times in both directions with your outside hand on the pommel and the inside hand on your thigh. When you're comfortable, put your arms out like airplane wings. Now close your eyes. Do it in both directions at all gaits (as your comfort and confidence allows).
Wear a helmet, and progress through gaits, closing eyes, etc only when you know you're ready. Be patient.