<p>All the blower fans for part cooling I've seen rotate counter-clockwise when viewed from the intake side. I'm looking to replace mine on an Ender 3 with something stronger, and one of the worst parts of the stock design is that it's offset by about 20 mm versus the nozzle position, requiring awkward duct paths that reduce the flow to get uniform coverage around the newly extruded material. A fan that rotates in the opposite direction, with air exiting on the right-hand size when viewed from the intake side, would be exactly right. Are there such models available, and if so, what is the right terminology to search for them by? Or is there a simple way to modify a fan to reverse its direction?</p>

I see that you have a minimum support angle of 60 degrees -- that may mean Cura Slicer isn't generating supports for that chin.  Try changing this minimum to a lower figure -- 51 degrees or lower.  From what I've read, most filaments and settings will allow 60 degrees with PLA, but this is the easy first thing to try to get that chin supported.
On looking at the photo again, I also wonder if what looks like a bad overhang print is actually supports that didn't separate as they should -- perhaps you only need to adjust your Z skip for supports to get them to come off the actual part better.
Following up, I saw a likely cause for this on one of my own prints yesterday -- coincidentally on the chin of a sculpture part.  What I observed is that supports for this region, which trailed up the body (as would those for your dragon's chin), likely due to their slenderness, repeatedly got knocked over.  The support structure "healed" over several layers after each such incident, but in a very fragile condition that would again get knocked off by a nozzle brush.  The solution to this is either to enable Z-hop on retraction (so travel doesn't brush the nozzle across supports printed in the same layer), or to reorient the part so the problem support is shorter and doesn't run right alongside the actual body wall.  Z-hop has less effect on other areas of the print.