Interesting, but as a Welsh homeowner and rotary driver, not much use in reality. Fast jet trainers rattle through the mountains at a few hundred feet and at 10 miles per minute... While you're bimbling around, enjoying the view at 100kts, these chaps rely on the Mark I eyeball most of the time - and so should you.
I also visited Valley recently and got chatting to some of the Hawk jockeys there (nice chaps). The new T2 models have TCAS but again, that's only really useful at higher altitudes. They file flight plans, but admit they frequently deviate from these without notice. You could visit the
MOD site for the low-level schedules or call Valley for Mach Loop, etc. timings, but even these change on the day, so can't be relied on.