Default operation has no dust issue, it has a variance issue. Small miners on big public nodes getting 1-3 shares a day. This is because of how public nodes treat miners as if they were all owned by the same person. I'm testing a change to that on vtc-us-east. Running your own p2pool results in the same thing. Smaller shares more often. But not dust size.

You can use ADDR/.00001 on any node to get the minimum possible share difficulty (ie: most # of shares possible), but the value would also be lower. When sharediff network wide is low, they can get really small. It's better to have a bit fewer payouts that are larger. But it's not good for someone to go a day or more and not get a single payment, due to variance.

TLDR: Running your own p2pool node is better for a small miner than joining a public node with lots of traffic. We're testing a solution to this though.