I think it would be too early and distracting to start putting in straw-man PEG syntax. Even for regexes, I intentionally avoided that this time around, but you can imagine something similar to what I posted last time.
Some links that were listed in String Consumption, but I'll highlight them again:
Perl 6's Grammars, which demonstrate a language-level integration.
Pegged for D, which demonstrates a library approach with compile-time integration and automatic cycle breaking for left-recursion. The reason I like linking to that library is, because like RE2, the tutorial/guide is excellent.
A paper that your link doesn't mention, but I think is interesting is Parsing Expression Grammars Made Practical, which uses annotations on expressions to make left-recursion, associativity, etc., possible and much easier to express. Manually doing sequences, associativity, and precedence in the grammar can be obnoxious and makes it harder to reason through. When you throw in error handling (ideally though explicit error nodes and some parse-state signaling), grammars can grow complex without these simple helpers.
I realize this is all unsatisfactorily abstract and vague at this point. We have fundamental building blocks to do first.