Personally I would say doing any more than continuing with the documented monitoring is over kill based on the occupation rates you've given us...but then thats just me, mind I've got some great pics of a cobra set up to achieve exactly what you're talking about Q.
Note that in this case the relationship between targets and the part likely to fail do justify action.
Its a large Lophostemon confertus with a very nasty injury at the base, more of a concern however is the crack evident running up between the two stems (red arrows)
A wider view portion of the canopy affected shown in yellow bit deceptive actually about 30% not 50%.
Cobra cabling to redirect in the event of failure
Direction of redirected faliure...yes the park owner still hasn't followed advice to close the camping site beneath the tree!!!
