From the "Features" page at rafsoftware.com:
Better external keyboard support: Allows for full screen display while typing. Support for Arrow Keys!
So I would expect that the arrow keys would function properly but it doesn't seem to be supported as of version 2.4
Another "quirk" is that when zoomed in, the bottom of the VNC server's screen doesn't come higher than the bottom-most button bar. This can be bothersome when I have the button bar with the modifier keys because the button bar blocks the bottom of the screen and it's hard to click behind it However, when in the other zoom presets (1:1, Fit Width, or Fit Height) the bottom of the screen can come above the button bar but if you've pinched to zoom after that, the bottom of the VNC server screen will no longer come back up above the button bar. It certainly is an improvement over the previous version that wouldn't come above the bottom of the screen when zoomed in so I'm glad to see this update in the interface.
Thanks for the great and affordable software, Raf! I'm glad to have found Remoter and look forward to its success!