Given that it is very easy, certainly when using isometric assets, to generate Master’s Toolkit graphic output files that are larger than the commercial VTTs can handle (e.g. Roll20 has an inbuilt limit of 10MB for a single upload), it would be fantastic to have as part of the graphic export function the ability to automatically* split the exported image into a number of “chunks” that you can stitch back together again in your VTT of choice. It doesn’t have to be anything fancy… you could either specify the number of chunks or the size you want the chunks to be. The tool is already doing that calculation for export to PDF when you pick a paper size.
To see what I mean, this map (two rooms joined by a corridor) generated a PNG of almost 22MB when exported at 70 DPI.