##### Description of the problem

#13993 introduced an optimization to `Box3#applyMatrix4()`

that only supports affine transforms.

– The geometry is transformed with`geometry.applyMatrix()`

`applyMatrix()`

.&`r93 Box3#applyMatrix4()`

– A`r92 Box3#applyMatrix4()`

`Box3`

instance is constructed from the geometry. A non-affine matrix is then applied.

For `BoxGeometry`

, it is expected is that both operations result in equivalent `Box3`

instances.

The `r92`

version transformed each `Box3`

vertex, then used `setFromPoints()`

to resize to fit.

**r92**: https://github.com/mrdoob/three.js/blob/r92/src/math/Box3.js#L562-L596**r95**: https://github.com/mrdoob/three.js/blob/r95/src/math/Box3.js#L562-L585

See #6039 for a similar issue with a `Vector3#applyMatrix4()`

optimization.

##### Three.js version

- Dev
- r95
- r94
- r93

##### Browser

- All of them

##### OS

- All of them

@razh Thank you for providing a well-written and clear demo.

I support reverting #13993.