[cgbeige]

the textures in the viewport don't display as a tile if the UVs are scaled outside the 0:1 UV space. They show as a stretch at all the borders.

[Mihnea Balta]

Due to a limitation in the Maya API, the viewport representation can't update immediately when you enlarge the mesh UVs. The texture will appear correctly if you make a small change in the material after editing the UVs, like touching a layer opacity or BSDF weight. We can add a "refresh viewport" button on the material to alleviate the problem, but we can't make it refresh automatically.

The 1.x plug-in didn't have this issue because it used Maya's internal mechanism for viewport display. Unfortunately, that is extremely slow so we had to come up with something different. The current system has a few drawbacks, like the inability to refresh when you edit the UVs or poorer image quality if large tiling or UV values are used, but the alternative is to take hours to open a scene which has a few dozen materials inside and suffer a 10 second freeze whenever you change a material parameter if you're using 512x512 for viewport textures.

The high quality viewport mode doesn't have these issues.