I've a question about possible usage of pogo pins in a commercial product. I've seen they have simply working principle and are easy to integrate in a case, some of that also have current rating up to 2-3Amps and gold finish. Is it possible to use them in this context? For example in an expansion board that don't require particular connection.
It's possible to use them, but it may not be a good idea in terms of reliability. I've used them on production test stands to connect to devices as they get built and they were one of the biggest maintenance issues. Pins would get bent, they'd bind and get stuck in the compressed position, something would loosen so they'd make intermittent contact and so on.
On the other hand, Apple uses a similar component in their MagSafe power connector for charging MacBooks.
You can personally I'd use something like one of these from Samtec rather than a random pogo pin mfg :).
I'd want to use hard gold on the contacts on the mating board surface unless maybe it was a one time insertion (but I would not plate the whole thing as hard gold). This will add an extra step and a little cost to the bare pcb but will protect against wear and oxidation. I'd also think about doing this of the product was going to be subject to any shocks or vibration.
Lastly single pogos would be a pain to line up in mfg without some kind if jig or holder so if you chose them I would pick the multi ones in plastic with guide posts that you show above.