I am lowering the ceiling in my apartment to run electricity, install spotlights, and avoid re-plastering an old concrete ceiling. The plan is for a smooth gypsum ceiling. The construction is: 28x70 wooden battens set with CC ~100 cm against the concrete, into which I then screw Norgips steel profiles at CC 30. On these, I will then mount gypsum across the joists, i.e., from left to right in the image.
My question: I don't have a frame along the room, so on the sides that cross with the steel joists, there is only support from each joist, i.e., at 30 cm intervals. Do you think this poses a problem, such as a risk of cracking? Should I mount profiles along the walls perpendicular to the longitudinal joists?