I was also confused about it. But i think it depends on the timing, so if he healed her right after she lost her hand, it would grow back. But now after her arm healed naturaly it can't be healed any further.Still find it weird that he can't heal shield girl's arm using his skills. Thanks for the chapter!!!
His healing abilities aren't sufficient on his own. If they find another actual healer, he can boost their abilities significantly.I was also confused about it. But i think it depends on the timing, so if he healed her right after she lost her hand, it would grow back. But now after her arm healed naturaly it can't be healed any further.
The missing translation on page 30 for 全て計画通り is "all according to plan".
All according to keikaku!That untranslated bit at page 30 is a pretty typical statement:
全て計画通り (subete keikaku doori) - "Everything is according to plan"