If a pawn promotes to a Queen, any piece taken by that Queen is worth only 1 point. That would make it worthwhile for rooks, minor pieces, etc. to attack that piece. That would make the use of promoted Queens more tactical and makes pieces already on the board better suited to be used as attackers.
If one point is too low then the Queen could be worth two to three points and any piece taken would be valued the same as the Queen.
Then its the regular checkmate points. The whole idea is to allow opponents to defend against that new queen without automatically losing significant points if the queen takes right away but if the queen is successful in checkmating it should get full value of the checkmate.
If a pawn promotes to a Queen, any piece taken by that Queen is worth only 1 point. That would make it worthwhile for rooks, minor pieces, etc. to attack that piece. That would make the use of promoted Queens more tactical and makes pieces already on the board better suited to be used as attackers.
If one point is too low then the Queen could be worth two to three points and any piece taken would be valued the same as the Queen.