I had the 'heat' problem with my Nordhavn. I had the 'darkening, see though film put on the saloon windows. Reduced the heat and provided privacy during the day. At night with the lights on in the saloon, no privacy.....
Same stuff they use on cars. I used to remember the degree difference, with and without the film but.... that went away like the boat.
On this American Tug, I had port light covers made out of cloth for privacy. Works pretty good for a heat barrier too. For the saloon, I have a double shade system. A gaze pull down shade and then a privacy shade to pull down. I used to remember the brand. They aint cheap, 6 units of various sizes about $1500.
The meek will inherit the earth but, the brave will inherit the seas.