First there is perhaps some slight refactoring that could be done. Though it does sound nice to reduce the dependency tree.
One thing is I like the declarative nature of the peg,
so I considered trying to make a tiny peg parser generator to go with it (Also worth noting that peg/leg itself is very small).
All that being said, a hand written parser could probably dramatically increase performance and not be that much more code - so I am still unsure - but probably.
Are you interested in contributions for a custom parser?