KalleKellosta: What can be done about that? One would be enough.
It's all or nothing, I'm afraid.
You can turn off the standard notification for replies in any of your posts of a certain CC thread, but the number of each is an uncontrollable variable. I'm used to receiving one or two, unpredictably scattered in one thread sometimes. Four is a novum for me.
Perhaps it's more convenient to collect WGT mails in one folder, by filtering(?)
As an experiment, you might change to another mail address of yours in the settings, and then change back if you like.
Have fun!