@ellemat2, FYI.
The ability to tile (useful only for already mirrored textures) and mirror (creates some beautiful patterns) can actually be very useful, especially when you have a lot of smaller texture images. Applying small texture image to a very large original image in the default use gets blown up in size. A woody pattern that SHOULD be repeated will instead look like a big wood-plank stuck across the much larger original image.
Not a big issue if you only use the high-res patterns included with Studio, but I imported 3000+ existing smaller textures with paper, wood, glass, ice, and many other things into Studio’s texture manager as new texture categories, and tried using those. Worked perfectly when using tiling (for some) and mirroring (you can create some very fancy patterns.
Hence my wish for a overlayed “grid” when resizing and restructuring textures. 
BTW… That resizing also allows you to rotate textures and THEN tile/mirror/extend. New ways of using fanciful texture patterning.
