If MC want more upgrade, he can learn about nanotechnology and create nanomachine to make him become a perfect cyborg like T-3000
Previously I was just no better than a bootleg Captain America with a bit of advantage like my cyberware enhancement. I could have gone full borg and be like Adam Smasher but I really don't want to loose my balls at the moment.
I think that's just the result when lizard gene in the formula interacts with it's host-human genome. Maybe some regulator genes in human genome influenced lizard gene's function when it was added into human genome