Thorfinn: I suppose. If they want to duplicate the problem, so far as I can tell, all they need to do is spend about $1500 each for 3 machines, then play for a couple hours.
Do you run a local server, then? And you don't have issues? What are the specs on the boxes you are using?
no I don't run a local server, I rarely play Terraria MP and when I do it's with my nephew to give him a hand and when we do play it's usually via Steam which is easier for him to do then the other methods. And yes I have Terraria on GOG as well as Steam(bought it on Steam shortly after release around 1.0.2 or 3 if memory serves and then again when it came to GOG) as for issues, I haven't run into any since 1.3.0.5 outside of a few sync issues but that's happening because someone else was using my wi-fi at the time.
As for boxes, man I usually play it on my low end laptop(my main rig is being worked on) and when I mean low end, I do mean low end, talking a 64 bit intel dual core pentium processor w/ a intel GMA X4500m intergrated graphics chip.
As for the devs, they don't do the testing soley on their set-ups they also have guys and gals that help do testing with them on the dev servers.