I think a pocket radar, or better yet a stalker video of his number is fine. If anything there are many PBR events where they will report your metrics but a reading won't be in the video, and that's always the case with PG. IMO video with gun is best, doesn't matter who gets it.
Re: shutting down. The latest my kids will pitch is Columbus day weekend, but a lot depends on previous activity. That said, it's usually not a complete shutdown. It'll maybe be 2 weeks of zero throwing, but then arm care with plyos, etc, but not pitching til January. This year after my 2020 committed in late July he completely shut down throwing so he could go heavy in the weight room for several months.But they don't generally pitch more than 78-85 innings a year.