When zooming in, I get "renderer is busy" which hangs the map for a second or two, and I was curious as to why. I'm running it locally so it isn't network bound. CPU does spike (for process "gnome-terminal-server") but doesn't seem to get anywhere near 100% (for any core). Do you know what it's waiting on when it prints "renderer is busy"?
Even though it runs locally, it is network-connected to the tile server that provides you with the vector tiles (unless they are cached locally after their first use). You currently have to wait for the requested tile(s) to be downloaded, processed, and available in memory before continuing rendering (which is slow in direct comparison to rendering itself). Could be improved by continuing to render the zoomed features of the parent tile until its children are ready (triggering a re-render) - but for now, it simply lets you wait until then :)
