I already tried to ad tags when posting series of posts to all blogs but somehow it creates an error and does not post to blogger.
So, I abandoned that strategy for now.
It could still be pursued and it does have potential but at this stage, there is no clear systematic way in place to do that.
An idea would be to ad the keyphrase within the label or tag for the post.
I just double tested and yes... an error is returned when trying to post a message with a tag on a blogger blog.
ok... It's clearer now - the error is returned only for the blogs which are hosted on my own domain names - posting with tags works fine when poting to a blog hosted on blogger
This would mean one extra optimized step
I could still explore that direction though...
To be followed...