Now I've got a usable car again can start coming out a bit more. Not really planned to go hard as spent most of yesterday driving (Hereford>Newport is quite hard when the A40 blocked, A49 shut (roadworks), A465 60 min queues (roadworks), and then once start heading towards Brecon got past Letton before the first indication that the A438 was shut too... home via Painscastle and a massive detour which I hope to never do again - but at least gave a chance to test the car).
As such, run was unremarkable, but this was the first time in a parkrun I've had to come to a complete stop not due to injury; having cleared some very slow runners on first straight, was passed by two people on dog power on long straight - but the out of control dogs started playing and got their leads wrapped up and took one of the owners down (as well as completely blocking path). They seemed ok so carried on.
Think I was negative splltting. First k in 4:23, and 2k at 8:48. Going harder second lap and gaining ground but some reserve left. Still nowhere near as fit as I have been.
GPS data is bollocks - I guess weather conditions (light-heavy rain and low cloud) didn't help, plus lots of fiddling re-setting the activity beforehand as it wasn't reading the HRM correctly. Latter seems to have been ok from about 1 min in onwards.