Use a balanced XLR out as an unbalanced L/R TRS out

 The following may be a familiar situation:

You are running out of outputs and the camera person / streaming person / ... asks you for a main L/R sum out.

One 'dirty' way to achieve this if there is a lack of space on the mixing board would be to be able to switch a balanced XLR out to an unbalanced L/R TRS out, as in old headphones, where T/S is L and R/S is R, for example. It is not a perfect solution, but it could be useful to have, say, four of these as optional extensions in medium budget mixing boards with limited space. For example, 16 outs can become too little pretty fast. 4 switchable outs would result in a total of 12 balanced outs plus 8 unbalanced outs.