UnityEditor.ModelImporterMeshCompression.Low stores incorrect uv data. Using Medium or High, stored data is correct.

To reproduce:
1.Open attached project
2.Open "Main.unity" scene
3.Select cube in the hierarchy window
4.In the inspector right click on "Mesh Compression Test (Script)"
5.Select "Store World Pos in uv4"
6.Right click on it again
7.Select "Set Compression Low"
8.Save the scene
9.Reload the scene
10.Select the cube from the hierarchy
11.Right click on "Mesh Compression Test(Script)"
12.Select "Log uv4 data"
13.Observe in console as the Transform Position values are different than in the inspector.

Expected result: stored values are the same as in the inspector
Actual result: stored values are different from the inspector

Reproduced on: 5.5.1f1 5.6.0b9

Unable to check for regression because no backward compatibility.

Win 10 Pro.

Screen recording attached.