There may be data left behind when the plugin is uninstalled, mainly because removing a block instance does not cause the data to be deleted. That is to ensure that not all points of students are lost when a block is inadvertently deleted. However, this should not cause the data to remain when the plugin is removed from the system.
There may be data left behind when the plugin is uninstalled, mainly because removing a block instance does not cause the data to be deleted. That is to ensure that not all points of students are lost when a block is inadvertently deleted. However, this should not cause the data to remain when the plugin is removed from the system.
To be investigated, and fixed if need be.