Grammar evolving
We see comparatives being made with "more" - more strong (as well as rendered as stronger). Is that OK? B. Can we innovate by saying, after making a serious statement, "At a seriouser level..." C. Can we say, "After the holy month I was slimmer but none the piouser." (As in none the wiser.) Otherwise you can never express this thought - "none the more pious"?
Solution 1:
Generally, it's preferable to use the comparative if there is one, and 'more' only if there isn't. There are no such words as 'seriouser' and 'piouser'.