Re: Making the most (or least) of a bad room.
Is the 35m depth the overall depth with the stage? How deep is the stage, does it fill the 15m to the main speakers? Is the 35m depth to the movable wall or is it at the 25m depth?
Might be interesting if that is what they have since they seem to have an asymmetrical pattern, 50 degrees wide at the top and 100 degrees wide at the bottom, but with that tiny horn the actual pattern probably varies all over the place and loses much control at a fairly high frequency.
Air absorption may be more a factor of the overall room volume, temperature, humidity, etc. but if you are actually addressing distance loss and increasing the distance keep in mind that you would be looking at the change in distance relative to the current distance, thus my question above regarding where the wall is located in relation to the overall room depth and the depth of the stage.
It's great that you want to help but watch out for people assuming that anything you do being perceived as 'fixing' everything and thus not requiring any further effort or being a failure on your part if it is not actually fixed. You might want to make sure they clearly understand and recognize that you are applying band-aids, not performing surgery.
Other than treating the room, getting the speakers up higher and aimed down to cover the audience would likely yield the biggest improvement. However, the speaker you linked does not reference and integrated fly points or provisions for flying so trying to fly it may involve an external 'cage'. Getting both the mains and delay speakers the center an minimizing overlap, if you then even need two, might also help with intelligibility.
