How to correctly implement scaling on Impress?

Question

Node.js

Hello.
Please tell me how to configure Impress correctly in order to get the maximum performance result. As far as I understand, based on the approximate config, it is assumed that each worker is launched on its own port:
ports: [3000, [1]], // Example: [81, [-1]]
Accordingly, with this decision, should I be responsible for balancing between the workers myself? For example, nginx or generally choosing a port on the client, and automatic balancing is not provided in principle?
It seems to be even a normal solution, and perhaps in fact the fastest. But on the other hand, I'm just interested in the other side of the coin: in various publications about Impress, including on github, I constantly come across discussions of some balancing strategies - sticky, multiple. What is it? I can't find it anywhere in the code. It's gone now, was it in older versions of Impress?
Thank you.