Ill shoot for the stars and ask for 4096 x 4096. I think that more then covers all of the needs that this program could be used for but hopefully isn't toooo computationally expensive! haha
That should be okay, probably a little slow at that scale, but it'll depend on your specs. I've changed the export dialog so that now the output scale actually renders at the scale/resolution you set (rather than scaling it up/down after), so once I release this update, you should be able to go as high or low as you like