Looking on the internet deeply has found these results:

moreover is the most popular phrase on the web.

what is more 191,200,000 results on the web	moreover 1261,000,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
And what is more, it is extraordinarily nutritious. And what is more, so do the police. For two weeks, the computers and their Internet connections have been incredibly slow and, what is more, a lot of Internet sites cannot be accessed. And what is more, I am utterly without illusions. And, what is more, if crisis management is inadequate, the problem uncontrollably spreads and worsens. And besides, what is more important? You are a notoriously bad student and what is more: That is perfectly in accordance with the Regulation, Mr Schnellhardt, and what is more, it is very pragmatic and also very simple.	It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

what is more

191,200,000 results on the web

moreover

1261,000,000 results on the web

More popular!

And what is more, it is extraordinarily nutritious.
And what is more, so do the police.
For two weeks, the computers and their Internet connections have been incredibly slow and, what is more, a lot of Internet sites cannot be accessed.
And what is more, I am utterly without illusions.
And, what is more, if crisis management is inadequate, the problem uncontrollably spreads and worsens.
And besides, what is more important?
You are a notoriously bad student and what is more:
That is perfectly in accordance with the Regulation, Mr Schnellhardt, and what is more, it is very pragmatic and also very simple.

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.