With any bitcoin or other altcoin address, I think the threshold to minimally inspect it would be the first 5 and last 5 characters. If you can check more characters or even the whole address, then so much better.

I don't think it's going to "scale" all that much even in the future, maybe if you're dealing with bigger amounts, you could look at 6 characters. And of course, for bitcoin I mean don't include the prefix in the count like 1 or 3 or bc1q.

Buying or selling coffee (or equivalent value), inspect first 5 and last 5, save a little time.
Buying or selling a house, inspect first 6 or 7, save a little time, the house is not going anywhere.
Buying or selling a car, check the whole address before it goes vroom vroom, because it's going down the road away from you ... but you probably have all the details you need, just in case, the payment would just be an irritating hassle if it went to the wrong address.