You'll notice there is an obstacle between GOZAX and HOLUN just left of the approach course at 710 ft. If your able to identify HOLUN, then you can be assured the obstacle is behind you, and the approach designer permits a lower MDA. If you can't, then you remain at the higher circling MDA.
My old garmin 300XL doesn't have step down fixes in the database that are beyond the FAF, but I can use DME to the missed approach point to determine when I've passed them. I think modern GPS units have probably every published fix in their databases nowadays.