You know, I don't know about the SLI hardware, but the resolution simply depends on the graphics memory as far as I can tell. To let Verve do its thing, it needs various processing layers in form of fullsized texture maps. In case of high quality, it even goes up to 4 times the size. Thus, if you have a 4k image, internally it actually uses a 16k image for a certain stage, next to a number of layers at 4k and so on... On my GTX 970 with HIGH QUALITY ON I can go up to about 3.8k, but with it OFF I could go well beyond it, but it would still get rather sluggishly slow then. Anyway, so, yeah, it's memory related. Anyway, maybe I'll come up with different approaches later on, too, though, my goal is to focus on the digital painting experience itself. I might have mentioned this before, but I will have a recording feature, which should then allow you to playback your entire painting at higher resolutions, if need be. This will get tricky, but could be the solution for large scale print work. What I find so weird is that people want to work in this giant formats, while 99.999999% of people, who will ever see their work will view it on a monitor, never "zooming into details" and so on. ALSO I have a 60 inch print on canvas hanging next to me, which looks absolutely gorgeous and the image was far less than 2k, if I remember correctly. Thinking practically, it just shouldn't be so crucial to go beyond 4k, if you asked me... but this could get ugly for me, if we were to argue about it, hahaha...
...anyway, I'm trying to be practical in a naturally digital sense. Good thing is, Verve will always be as good as the hardware permits, so, it will get better as hardware gets better!
VRS are literally settings, which is a different word for "preset"... Pre-set = setting created earlier. So, yes, I could and just might hook up buttons you could assign to settings. I have long since planned to offer customized settings saving, where you could check or uncheck what kind of settings you want to save or load. Currently settings (.vrs) save everything but the image content, meaning it saves all global settings (fluids and so on) as well as all brush settings.
I realized that it could be useful, because you may have come to some finely tuned settings for watercolor like effects, or charcoal or oils and so on, which you could load by loading an image you've created that way, but you may just want to switch in the middle of a painting process to any of those settings you like... so... that would be the purpose of them!