First of all, this is currently not a bug. It is the extended behaviour. We're not rounding, we're cutting off everything after the decimal point for such large dicussions.
Now, the question is whether that behaviour makes sense and, if not, how best to change it. We clearly have not much space in the sidebar, but there might be enough space to implement the suggestion by Davis.
If I understood you correctly there, we will always show three or less digits, and if there are less than three digits before the decimal point, we can have a few digits after it. That is typically pretty easy to implement with functions such as printf in PHP. However, it seems like there's no comparable function in JavaScript, which means we'd have to use an external dependency such as this one. Not sure whether that's worth it for such a small feature.
In the end, it all boils down to whether we have enough space in the sidebar for up to three digits and a letter. @Toby probably knows...
