Not in Perilous Journey (so far), but Paisley Brickstone, kinda. The two kids who are the most "self inserty", without being direct inserts, are two that will be introduced in Chapter 1 that are twins. One just got semi-introduced this week in the prolog, but the other won't be introduced until December, probably. Pierce is a hothead and Fenmore's a smartass and they're constantly bickering because Fenmore doesn't know when to keep his mouth shut, and Pierce doesn't know how to control his temper when Fenmore's being a prick. Here's some stuff of them:
Sketch from Chapter 1 of them giving each other the stinkeye (circled them)
Sketch from Chapter 2 of Fenmore being smug and Pierce getting pissed:
Might be very minortly spoilery but information like this gets casually dropped in my comic to no fanfare anyway since all the characters know each other for the most part and it's just the reader and Harvey who don't really know anyone (and Harvey's too quiet to ask).
But yeah, it's like you where they're not supposed to be actual self-inserts, they both just ended up with the flaws I feel the strongest. I did directly put myself in the background on a couple pages but I won't be pointing them out BECAUSE REASONS.