I decided to go back to Rafute and try and improve my score today. The result is the below score: 177,568,390.
The world record with Rafute is 233 million, which I consider to be the most impressive among the world records for this game in the 1 loop course (for reference, the record with Momo is 260 million, while with Ikuo it is 250 million). I can see how it would be possible to get a few tens of millions of points beyond my score (up to 210 million or so), but trying to find 56 million extra points is beyond me.
In regard to my own patterns, I made very few mistakes with them in this run. I did fail to score with the lard attack on the final phase of the last boss, but I scored on all other phases and milked the final phase with three bombs.