Hello Arvid,
Thanks for getting in touch and for confirming that hotkeys are a feature that is indeed useful, we do love it ourselves...
However, I'm afraid I don't have particularly good news for you. Implementing the hotkeys functionality in EPPI-Reviewer Web is in our plans, but not scheduled within the immediate development queue, at the moment. Main issue is that there are many functionalities that EPPI-Reviewer Web still lacks completely, and we believe they should take the precedence.
Our immediate aim is to reach the point where doing a whole review from beginning to end is possible while using EPPI-Reviewer Web only. Once this is done (and it will still take some time!), we'll start implementing the things that we see as "nice to have" (as opposed to: "can't do without"). Hotkeys are very high on the list of "nice to haves", but not being essential do get things done, they are not our top priority overall. We do understand that they are the kind of thing that does make a big difference in the real world, though. So, after all, we will try to sneak them in while still working on "must haves", but I'm afraid this is the kind of endeavour we approach in an opportunistic way. If it happens that one of us needs to fill 1-2 days development time with something, that's one of the tasks that could be picked up, depending on what else is available at the time.
Bottom line: we need to be patient. Hotkeys will appear in EPPI-Reviewer Web, but we can't promise (or give an indicative idea) about when they will, with our apologies.
Sergio