He hadn't even finished going through all the parameters that he wanted to be able to adjust, and he had finally arrived at the last on his list.
('Healing,')
This was normally not a parameter as it was a constant. Yet he didn't think that it was something that was inescapable. It would be quite convenient for him if he was able to increase the rate of healing in times when he was gravely wounded. One time that immediately came to mind was the time when he was chewed out by the Root, allowing himself to heal at a much higher pace, recovering sooner.
Who knows, if he had that ability back then he might have been able to catch the Martial Squire who left, leaking intelligence to Chairman Deacon that eventually led to the discovery of his identity.
Regardless, one potential path forward in this particular parameter was the Hungry Pain technique, of course. But he didn't want to bank only on that technique.