Complain to Dunlop? Might be worthwhile as 6100 miles is unduly short life. At 12500 miles (first A-service) my Dunlops 175/65R15 were measured as... fronts 4/5/4mm across the tread, rears 5/6/6mm.
I'd say, despite what Honda assert, your fronts might suggest a tracking issue... too much toe-in. By 12500 miles, both my front Dunlops had excess wear on the very inside edge... not noted by the technician's measurements. Too much toe-out. Honda technician asserted 'tracking OK' but, as said, he hadn't noted the markedly excess wear of just one inch width round the very inside edge of both tyres. I had the tracking checked and then adjusted by an independent tyre fitter while I watched and tyres 'rotated'. £26... Honda quoted £45 for the tracking alone; it's not a warranty item - understandably. Though I'd swear my GE Jazz had never been kerbed or hit an unduly large pothole to knock tracking out of whack. I don't normally rotate my tyres because, for safety, I prefer best tread always on the rear but I want to see what happens to my now reasonably evenly worn fronts before renewing them. And we are moving - hopefully - into drier weather/drier roads.
Your rear tyres? The wear on both outside edges you have described sounds like the classic symptom of a tad underinflation.
New tyres? I have seen Culzean recommend Michelin Energy Savers on this forum because they are 'quiet'. I've had them on my cars previously and like them for that, good ride, pretty good all weather grip... and for slow wear.
In my Honda dealer the other day, I noticed a new Jazz in the showroom was Michelin Energy Saver shod. Michelins can be had from Costco at a very good price... Mytyres online worth considering, too.