I am using slide film for more than 20 years now, and I have never experienced serious problems with blown highlights.
Maybe I know how to meter the exposure.correctly....😉
Life is easier if you project your slides: Even if you "expose for the highlights" in most cases you see detail in the shadows on the screen with a 250W projector.
And there is a simple trick to get one stop more dynamic range with slide film (and with negative film, too).
An old trick often used with BW negative film and the zone system.
You can use this trick in all cases when using a tripod and having a camera with double exposure option.
1. Know the dynamic range of your film.
2. If the dynamic range of your film is about 6 stops (e.g. Velvia) or 7 stops (e.g Provia), and the dynamic range of your scene is one stop more, you can make the following:
Meter the first time for the shadows, so you can get detail in Zone II. Then stop down for 3 - 3,5 stops.
Then the double exposure option. Next exposure on the same picture. Then you make your "real, fulll exposure", which is exposed for the highlights.
With this trick you get visible more shadow detail, but without blown highlights.
Why? Because your shadows in Zone II get 3x light instead of 2x.
And your highlights in Zone VIII get 129x instead of 128x, and this one doesn't affect the highlight, the difference is too small.
But the difference from 2x to 3x in the shodows is significant and visible.
Knowing the Zone System is also helpful for slide film shooters 😉
Cheers, Jan