Hello for your comfort to work with me if you want, i personalty suspect the gypsum board is drawn in your skp file is not accurate , There are more details.
My specialty on ceiling is gypsum board ceiling. im willing to work on your project but as it is a remotely work, I require captured images of the location and i have to make a floor layout first to determine ceiling design category. and then i can show you some out put. this is how i make the masterpiece.
Feel free to inbox me for more discussion.
Many thanks!