Any time you get LF1 advancement you are 'at risk' to get chimp lip. The above are potential mitigating or exacerbating factors
Operative concept is OVER advancement of the maxilla; advancement in excess of what could actually be avoided if the surgeon had all the right 'tools' in his box. Although sometimes, some unwanted advancement can't be avoided and can be considered a 'trade-off' of getting a LOT of OTHER aesthetic problems improved. So, here I'm defining 'over advancement' as type that could be avoided rather than that of a trade-off that could come from a surgeon needing to correct a 'boat load' of aesthetic problems where a 'trade-off' of convex lip can't be avoided.
The risk is lower if one starts with a short philtrum, overly acute nose to lip angle and maxillary recession. Have a look at the photo Plosko entered and my response to follow my drift.
One exception I can think of to that is if someone, in addition to having a recessed maxilla (class 3 type), the ALSO have EXCESS lower jaw advancement. Like class 3 with recessive maxilla AND pro-gnathic mandible and they get ONLY maxilla advanced to match the pro-gnathic mandible and not a BSSO to set the mandible back. In which case, one would get an OVERLY advanced maxilla where the over advancement would be proportional to the the BSSO set back that was NOT also done.
Risks are higher, and IMO, the highest when the doctor wants to do LINEAR ADVANCEMENT of both jaws by an equal amount when both jaws DON'T 'need' to be advanced equally along their 'native plane'. Classic example of OVER advancement of the maxilla is in a sleep apnea case where one wants to expand the airway where instead of the doctor doing a CCW rotation of the maxilla to minimize unwanted maxillary advancement and maximize wanted mandibular advancement, maximization of the mandibular advancement comes with the aesthetic 'cost' of maximizing UNWANTED maxillary advancement AND along a NATIVE PLANE (diagonal) that's unfavorable to aesthetic optimization.
So, those are 2 examples of OVER advancement of the maxilla. There are some maxillary advancements that can be quite favorable to the nose to lip angle and contour.