User blog comment:Fliu/Chapter 987: Now It's War!/@comment-47.26.5.186-20200811020049/@comment-30281369-20200813132606

Aging Momo wouldn't help much. Even if his body becomes stronger, he himself would lack several vital factors that would help him make use of it. He would still lack skills, techniques, experience, and also Haki (all the which he could only gain via training and fighting experience); He wouldn't be much help in the battle besides maybe at least being able to get himself out of danger and hide until the fighting is over.

Lastly, I don't think Shinobu powers would affect Momo; I think that falls under Jewelry Bonney's Devil Fruit power.