My position is: do not demand anything from your customer! You have to adjust to his/her requirements as much as possible. If the stage does not meet some requirements, you can adjust to them. Where there is a will, there is a way.
The most unrealistic stage on which I've performed was a 1.5 m x 1.5-m one with a height of 2 meters. It was in a nightclub. The audience stood below, and I was blowing soap bubbles on the bar counter. My performance went excellently, although the "stage" was very small.
We thought for a long time how to work on such a stage, and, as a result, the performance did take place. Therefore, I believe that you need to be able to adjust to the customer's demands, rather than dictate your terms to him/her.