@alberto__segura offhand, I do not know if those services support changing a notification if it had already gone out.
That'd be best...
I used the telegram plugin and it's true that I was receiving too many notifications.
Perhaps if the forum will send 2 variables it will be easier for the plugin to cull the notifications to avoid sending too many. For example: one variable might say the type of notification (if it's a mention, a message favourited, new answer, etc. ) and another variable might say if there is another mention, message favourited or new answer that haven't been read in that post. (@alberto__segura may that works?)
After all, from what I've seen (as a user) is that little things is what makes people think that nodebb has hundreds of differences with other platforms.