Also it's a bit hard to judge what the number of open issues means right now, because we use github issues also to track internal tasks (for better visibility). So as we have more engineers and more users there will inevitably be more open issues/PRs at any given moment.
Yes that limitation was removed and you should be able to use the node graph in dashboards with any datasource providing you can query the data in the right format. In Explore though such query will still show the data in a table if the meta property isn't present. We hope to improve that later on.
Also it's a bit hard to judge what the number of open issues means right now, because we use github issues also to track internal tasks (for better visibility). So as we have more engineers and more users there will inevitably be more open issues/PRs at any given moment.