Suggestion:
Wouldn't it be a good idea for the protagonist and his companions to train under the influence of Gravity?
Also using Heal Pulse, so they could cycle: train to exhaustion under Gravity, use Heal Pulse, and go back to training again.
I hope the training process + discovery of the evolution method + the evolution itself doesn't take so long, it gives me nightmares the chance to end up spending 100 chapters waiting or something