I've been running one at 50 watts for years. No problem.

Me, too, on HF and VHF-- 50 watts out through the things. I'd even used them on
coax with stranded center conductors, but the conductor first, though, has to
be carefully prepared, including tinning and shaping the end. It then needs a
slight twist with the push, else it'll just bunch up at the back and short out
to the shield.

That flexible coax use was for a deck mount VHF antenna on a turtle back
company car I used in marine electronics service. The connection survived well,
but the flexing from frequent opening and closing of the rear door broke the
center conductor strand by strand until...

Bill, K5BY