A family of Microsoft word processing software products for creating web, email, and print documents.
I agree, losing the ability to edit in Read mode is massive. From Microsoft's point of view, I can understand that editing in Read mode could cause unpredictable behaviour, simply because Read mode has limited ability to show the user the results of any editing or formatting. But Read mode is great for proofing a document, because I can set the view to maximize readability and convenience and it would be great to have some limited editing functionality.
I'm using a Surface Pro 3 and am able to use the digital pen for marking corrections while proofing. In Read mode, I can use the pen to highlight words or passages that I want to revisit. I can mark a bunch of things, and then switch to Print mode and attend to them. (I don't mind doing it that way, because it suits the way I work: it allows me to read a passage in its entirety, before going back and making the corrections.) To do this, I use the pen to select some text in Read mode, click the context-sensitive button (the one that's equivalent to the right button on a mouse) and tap the selected text. This opens a pop-up menu that allows me to choose "Highlight". I can also choose a colour from a secondary pop-up sub-menu, but just tapping "Highlight" will apply whichever colour is pre-selected.
You can do the same thing with a mouse: select some text, right-click, and then either click "Highlight" to apply the existing highlighter colour,. or choose a different colour from the sub-menu pop-up.
It would be great to have more functionality than this, but I understand the inherent limitations. For example, some editors might prefer to use the pen to circle words that they want to go back to later. But if you circle a word in Read mode, it's highly likely the circle will no longer align with that word once you switch back to Print mode.