Many of the programs I use require that any downloaded tileset has its origin (Tile_0x0.png) in the southwest corner. UMD names tiles in a North to South arrangement before moving East for the next column.

I think it would be useful to have a dialogue that allows a user to choose which order the naming convention applies to the tiles that are downloaded. For instance today I had to rename 8134 files to align properly as X-Plane scenery, and even with a batch tool it took 4 hours due to the tool not catering for renaming a grid tileset so the Y axis was reversed.

My personal need would be for the first tile to be the southwest tile and the northeast tile to be the last, but also horizontal progression that build rows instead of columns from NW-SE and likewise for SE-NW could prove useful for some users.