I had been testing several options to use the LTE iPad as remote Mac OS client. I decided to go for Parallels package (at least for a year) after all. Since it works well with my touch keyboard folio from Logitech, I feel it's almost there to call it the best on market. As an app, I understand how "command" shortcuts has bit of limitations from iPad OS... and I can accept that as a trade off. But adjusting the display resolutions with toolbox, I feel it should be fair enough to say not having an option to get the right ratio for modern tablets (without digging into terminal) is bit of a lame. All the emulated OS's runs on the base display size, I wonder why any other users haven't suggested the feature yet. Please consider the update for all the iPad Pro/Air4th users sake.
