That is an amazing idea. Like a "strength o meter" that has a progress bar filled with a color and if it is completely filled all the way to 100% strength, it is the best possible move.
The only way to improve that was if it were clickable and it gives reasons for the strength of each move in a pop up when you click it.
I don't think any other chess site in the universe has such a thing and it would be crazy helpful.
It would be nice if the staff will consider to add a personal repertoire page where it will be possible to insert moves and add the move strength in chess notation or in engine values. Obviously this page must be private. As an alternative it could be added to the personal games explorer page the possibility to add move strength to every move. Thanks and best regards