I made the suggestion of 10k because that's the amount most leases are quoted at. So if the vehicle was a lease trade in, you can have an idea of the mileage put on it. The "average" is 12k per year according to carfax. I'm not suggesting that an MDX can't survive extra miles per year. It's just a way i used to judge the value of a used MDX in comparison to the price being asked.Unless a person is very wasteful with money, most would have more than 10K miles on it within a year anyway and most wouldn't get rid of a vehicle after just a year due to miles of 12K. Most vehicles still seem new and have a long ways to go even after 3yr/36K miles, and 5yr/60K miles and my 2014 still feels new to me after 8yr/74K miles. This means when looking for a used vehicle getting something with 30k-50k miles would still feel and behave pretty much like a new car.
More important is whether there's any factory warranty left on the vehicle. It's reassuring and sometimes handy to have at least a year of bumper to bumper warranty left on a vehicle in case something silly happens to it and even more reassuring to have a powertrain warranty still - without having to buy an extra extended warranty which I'd never do. The last time I checked Acura has 4yr/50K bumper to bumper and 6yr/70K power train warranties as standard.
The warranty was the most important part for me. CPO would be best as it adds to the original warranty from date of purchase. But remaining factory warranty is good too as it gives you a way of fixing any issues that may arise with your new used vehicle. Any MDX that's 2019 or 2020 should still have factory warranty unless the previous owner put a lot of miles on it. I did see a 2019 hybrid advance CPO with 44k miles on it. Even though I was able to negotiate the price down to $38.8k, i still felt it was too expensive for the mileage.