I am looking for a workflow to export not only the tile I see, but also the one that would be on top/left/right/bottom relative to the visible texture. Since Designer is procedural, it should be capable of generating data "beyond" borders of the visible document. Is there some feature to export such "tiles"?
One thing I found is the Tiling parameter of Materials->Default->Edit. Scaling it up, the texture gets smaller in a nonrepeating pattern. Thus the following imaginary workflow could work. Does somebody know how to actually do it?...
1. Set Tiling to 2
2. Export upper left quadrant in full resolution (e.g. 4096)
3. Export upper right quadrant in full resolution
4. Export lower left quadrant in full resolution
4. Export lower right quadrant in full resolution
Maybe there's an easy Designer feature for this and I just don't know about it.