I have not used vundo, but it seems to be just a visualizer for the buffer undo list, whereas undo-tree takes over the undo system, replacing not just the comma

I have not used vundo, but it seems to be just a visualizer for the buffer undo list, whereas undo-tree takes over the undo system, replacing not just the commands but the data structure (https://github.com/apchamberlain/undo-tree.el/blob/help-in-visualizer-frame/undo-tree.el#L1677-L1726 https://github.com/apchamberlain/undo-tree.el/blob/help-in-v...). In other words, I think there's simply less surface area for vundo to have or cause problems.