Regardless of the resolution set for the Octane viewport, it never opens a window larger than 1280 x 720.
My monitor is 2560 x 1600 and 4k monitors are very common now. If my Kernel render width/height are set to 1920 x 1080, that's what I'd like the Octane viewport to open at. As it is, it opens at 1280 x 720 every time, which is 71%, and I constantly have to resize it and zoom to see 100% of the output.
I have this issue on two different workstations. It's a minor thing, but it gets annoying because it happens every single time, and there's no good reason for it.