When I upload to postimg I have it resize the images to for a19" monitor comfortably. I forget what resolution that is. Bigger than those you guys use for sure. But I prefer larger images. Not scroll the page big, but bigger. I use a 32" monitor (1080p) in both the garage and the office (4k) and a 75" in the living room (4k) so screen real estate isn't usually an issue. But small pictures sometimes can be a problem. I'm sure I'm an outlier as most probably view the forums on a smartphone.
I'll DL tapatalk x5only and have a play with it. Certainly would make posting images from the phone easier. I commonly use pics from our dslr which is another reason for postimg.