my one attempt to plf back in the student days circa 2003 did not go well. I was on a 288 manta, probably 3rd jump, and was told if your radio doesn't work, half-brake landing and plf.
my radio didn't work.
I landed way out and dutifully got on to final with my hands at ear level, feet and knees together and flexed and waited to hit the ground. and did i. somehow i bounced flipped up and landed on my neck / head.
i wish there was video, as to this day i don't know how that happened. but my plf training was completely inadequate for a half-brake landing on light wind day, even on a big manta.