Hi, I am loving the new additions to the app, its very quickly getting to the level of allowing me to do pro work. The only thing holding it back is file sizes. Doing illustration work, I need larger files with higher DPI. Like doing comic pages, I would prefer a 10x15 page at 400-600 dpi, which is what I work with normally on the desktop app or in Procreate or the other drawing apps. I would absolutely love to see this in Sketch. If you're only going to allow the page dimensions for comic pages to remain at print size, then the higher end of the DPI is an absolute must. Are larger page sizes something we might see in the future?
Glad Sketch is becoming more and more useful to you; this is definitely feedback the product team likes hearing (so I'll make sure it gets back to them).
And a definite yes to custom canvas sizes and higher resolution. Unfortunately I don't have a date for when they'll be added, although I suspect either one or both will happen sometime this fall, but both are definitely being planned and worked on.
Sorry I don't have more information for you but I hope that helps a bit.