Hi, yes, you are right, fewer cucumber plants and spread apart is the key with this method. It also helps to have a taller trellis height.
I tried it first time last year in my raingutter-bucket setup, with four, 5-gallon buckets in a row. As a result my trellis is a bit short, and the narrow diameter of the buckets puts things way too close. I couldn't keep up with the growth and suckers, they ended up climbing all along the top, tangled up into a leafy mess and then powdery mildew hit them within a month of production
My relative humidity is high around 70-75% in the summer given that I'm coastal, but water saturation in the air will not be as much as yours since our temps stay a bit lower for most of the season.
This year we're concentrating on tomatoes, but I think we will try this in the ground in 2024 season and will keep the plants far apart. The lower/lean trellises are short at only 5ft, but it's by design for my aging parents to be able to reach.