Hi, I've been using Substance Painter on Steam and it's been a great help to my 3D Modeling process. However, there are a few shortfalls in that I can only have one symmetry axis active at one time, which while alright for some things, can be a bit of a hassle in other workflows.
I know of some workarounds, namely slicing an object through its axes, mirroring it, and then merging it together to create mirrored UVs. However this doesn't work with some workflows. Likewise, using the transform or mirror filters also doesn't work in some respects.

For example, these ships are mirrored in the x and z axes.
I textured them by mirroring the model along both axes so that the various heightmap stamps and color decals are identical in placement along both axes.
However, if I had used a normal workflow that would have meant having symmetry active on one the x-axis, and then painstakingly painting and repainting the same decals and stamps on the z-axis with the paints on top as reference.
This could be simplified by enabling symmetry on the vertical and horizontal axes at the same time.