Just curious here, not throwing stones, but how dark is the room during the day? I don’t see the need for the Christmas lights if your getting daylight anyways. Other than an indication of day and night they don’t need much else. I just think having a light during the day gets played on a little to heavily. My snakes have led lights but I only use them when their tank is dark usually in the evening. I may need to see in the tank at those times hence the lights. Otherwise the daylight in the room is sufficient.
My thought is the heat would be my primary concern and then the light if that indeed is an issue. I realize your giving your all and I don’t want to squash your spirits but maybe the lights are not as important here as the temperatures. My snakes generally hide all day when it’s light out so just a thought.
BP’s get the vitamins they need from prey other than sunlight like other snakes that do require specific lights. Breeders keep them in tubs that most likely only get a glimpse of light through a crack on top of their bin.