Turns out I did visit Innes again in spring, I just got back from another 3 night trip an hour ago and this time it was a roaring success for brown snakes! I managed to find four different Peninsula brown snakes over the course of my stay, mainly outside the national park and in surrounding parts of the Yorke Peninsula instead. I had a particularly close encounter with one large individual which stayed still and allowed me to get some nice shots (pictured below), before I stamped my feet to get it to move off the road and not become roadkill. This is the second species of brown snake I've seen in the wild now, and if things go to plan I may also get a chance to see western or strap-snouted browns later this year.
Snakefest aside, the next most exciting animal encounter I had was with another malleefowl, once again in a place I completely wasn't expecting it (in an open area not too far from the visitor centre). I got a much longer and closer view this time, leading to significantly nicer pictures!
And here's just some other pictures I took while away - a sleepy lizard/shingleback (moved approximately 2,356,824 of these guys off the road over the course of this weekend), an emu, a mob of reintroduced tammar wallabies and a tawny-crowned honeyeater.
The herping season has started here now so hopefully I'll have some more exciting reptile encounters over the coming months!