Freeze dried actually has the same nutritional value as frozen after being soaked to soften and readd the water lost in freeze drying. The issues most people have with it are bloating/constipation due to the betta not being used to the lower fiber diet and overfeeding because the freezedried seems like less when it actually isn't.
The pellets I feed are at 45% protein. I supplement with freeze dried blood worms, freeze dried krill, and freeze dried meal worm guts.
The blood worms are 50% protein, the krill is at 60%, and the meal worms are at 48% with higher fat content.