Scorching Conservatory - reflective roof film?

[Blackcats7]

Has anybody tried this please?
Had a quote for coolkote film to be fitted inside the polycarbonate roof, allegedly reduces the heat by 40%. Quote is £650 for conservatory approx 8m x 4m.

I have a hot conservatory, but don't want to spend money on it as it's not something I intend to keep long term. I'm planning on painting the inside of the roof polycarbonate panels white. it'll be quick and easy, I don't need to see out through the roof so happy to just white it out. it should reduce the heat substantially and if it doesn't I'll have a rethink.

We looked into this but didn't want to spend that much.

Our roof is flat and rectangular. We bought a good quality, made to measure dark grey tarp the exact size of the roof. Just laid it on top of the roof panels outside and dh fixed it in place using white cord through the metal holes at each corner, which is invisible against the conservatory.

Cost about £45 and looks neat and tidy. No glare inside and the temperature has dropped by loads.