For my admittedly small 12"
, I used RV levelers on top of concrete blocks. I used 16 of them in this pattern. My site in on an incline, with a 12" drop from front to back, so I raised up the front set, and dug in the back set. In retrospect I would rather have put the low set just above grade, then raise the front up more. For each block, I leveled it, packed it down with a tamper, then filled it with road base a few inches deep, then tamped that down using the block itself. I put the required number of concrete blocks on top the tops were all as level as I could get. I then put the RV levelers right in the middle of their range to allow for settling and movement. With this system, you permanently have the ability to adjust the height of each leg up to the limits of the levelers. In the unlikely event that you hit the end of one or more, you can re-do ALL of them if necessarily. That requires your plumbing to have a small bit of vertical flexibility, but if you're not making something truly stationary like a concrete slab or deep pylons, you should include that anyway. The levelers aren't too expensive (I think I just paid $50 for 4, and you get them cheaper in bulk) and I think each one is rated for 5000 lbs, so it's ridiculously over-engineered. The other consideration is something to prevent sideways movement of the yurt strong enough to move it enough to tip all the levelers. You could use dog tie out or similar to put downward force on it if you were in a very windy environment. I've used this system for 7 years in the forest in Texas, and I've had very little settling. When I do, I just get a laser level, get under there, and dial it back to level. Finally, if you have one or more feet that is really whacked, it's very easy to remove one leveler and fix the structure while its deployed. Worst case you put another temporary leveler next to the one to be fixed, do the repair, then put it back.
In my case I seriously over-engineered the number of levers because my goal was to have a platform that would come apart into no larger than 4x4 pieces so it could be transported by an average sedan. That means I have tic-tac-toe board of nine frame 2x4 pieces that bolt together. And *that* means my cross members aren't a single piece, which really lowers the rigidity of the platform. If you, instead, use traditional deck-building techniques with large, single-piece cross beams, you could use far fewer levelers to get the same effect.
The only problems are that this design is potentially higher maintenance, and you need to preserve access to the levelers, and because I dug the back feet into the ground, water goes in there when it rains hard and makes them sink a little. Still, after 7 years and a yurt filled with furniture, AC, fridge, huge cargo bed, etc., I've only very rarely had to adjust anything.