Searching an issue number in the list page's text input should take me to the issue. Sounds small but it's a frequent irritation; I will be 200% happier with Gitlab once it's solved, and my teammates even more so.
If you have Alfred, you can set up a custom web search since issue numbers are in the URL. I have tons of these set up to get to different repos, my global list of PRs, etc. It's that much faster because you don't even need to open a browser or navigate to the page to type in a search field.
Interesting idea, but it doesn't really fit my use case, because I always have a tab open on the issues list page for each project on which I'm working at a given time. When I want to open tabs for issues of present interest, as when reviewing for deployment or preparing a changelog update, it'll be a lot more convenient to do so by searching issue numbers and middle-clicking their entries in the result, rather than the current method of copying a URL to an issue page, then doing C-TAB C-l C-v <end> <backspace> <backspace> <backspace> <backspace> 1 2 3 RET with as many issue numbers as I have in hand to deal with.