Oh no! Was it ok? The track above was extra rough and slippery taking lots of concentration as you anticipated.
The lack of stability is what really annoys me...I mean, I've been standing on the damn wobble board (AKA whoopee cushion) for a year now and it makes no real difference. Plus these days ankle gets aggravated by even long runs, and swells up after forest orienteering. So that makes it hard to enjoy O although I am looking forward to the Flinders events!
Try some yin yoga instead of the wobble board... I'm finding that is helping my feet and ankles recover for that unfortunate experience with the stairs in the last sprint race in NZ all those years ago.