I have three wave boards, Patrik 113 QT wave, Exocet 101, Angulo custom thruster.

I use different fins for each board but the areas differ in a strange way.
QT Wave 113: 1 x 25cm Maui ultra Plus 2 x black project 10cm sides. Total = 329 cm2 ( usually using a 5.8m sail )
Exocet 101: 19cm MFC TF Plus 2 x Ezzy 3 degree side. Total = 352 cm2 ( Usually using a 5.3m or 4.8m sail ).
Angulo 89: 1 x 20 cm Black Project plus 2 x 10cm Black project sides. Total = 296 cm2 ( usually using < 5.3m sail ).

I'd say the board with the most grip was my Angulo which also has far deeper concave and the board that planes the earliest was the Exocet 101. The QT wave does seem draggy but seems the best float and ride and easily the best in back side conditions where you want to nose to be pushed back off the top.

Therefore I don't think that area is completely the whole picture.

I used the various fin websites to get the areas. Ezzy 93cm2, Black project sides 56 cm2, Maui ultra 217 cm2. Black project main 184 cm2.

Sounds like you need more Tow or is it Toe

You forgot to write random words in capitals Rider

More concave can give more bottom turn hold and a feeling U can push harder and change your planing threshold a lot