History_Stat add property

What do You think adding new properties to a component?
I mean value_template and unit_of_measurment..
I need to count binary_sensor changes. These changes concern the consumption of coal by my heating stove.
One change corresponds to 0.181 grams of carbon. Unfortunately I did not have a way to pass that factor to history_stat.
So I made a template_sensor that used history_stat. This trick did not work, because template_sensor did not want to update. Finally, I modified the source code

Blockquote
if self._type == CONF_TYPE_COUNT:
return round( self.count * 0.181, 2 )

This is not a good solution, because every update overrides changes.
The solution would be to add two new properties.
The may also be uesful to other users ?

Regards