WELCOME, ROB!!!
Put a middle brace in there. The piece of mind it will afford is priceless. Since you are asking, you are wondering or worrying. Put that to bed the easy way. Worst still would be if the stand failed at that point sometime in the future and you will kick yourself for not putting one in. There is nothing wrong with overengineering a stand.
Look forward to your build thread with ALL THE PHOTOS!
Share and like often!