I use a Bluetooth hardware keyboard on my Note 4 when I am dealing with email while travelling (eg plane, train), which is why I picked AquaMail because in replies, it properly inserts > characters in front of the original message text.
What's missing from the editor, however, seems to be any kind of keyboard control except up/down/left/right. Is there a way to delete whole lines without having to fiddle with the on-screen highlight widget, which is horribly difficult to control. Just a simple Ctrl-K or similar would do.
P