For the feet, there's three manufacturing way.
1. Non- standing.
The feet in this way can not stand even leaning on something.
2. Standing with bolts.
The feet in this way will be installed with the bolts in triangle .
3.Standing without bolts(For silicone doll only)
The feet in this way will be made with hard silicone material which make the doll standable
Generally, standing with bolts stands longer than without bolts. Even though, both standing way is not stable. Leaning on something is highly recommended.