I agree with Wolfpack98 most of the lag is due to the users computer, I have experienced this first hand.
I have experienced some lag during playing and the other players beside me experience nothing. When I checked my internet contactions they were running fine what I came to was that after running diagnostcs on the computer the system was all bogged down and my CPU usage. Now before you say anyithing the computer was not running any other programs, just freelancer.
Another instance of this expample is when I fly into a heavy gas cloud like the one in Newcastle, the masive geometrics of the gas cloud over load my computer.
The reason for this is that the Discovery Mod is a massive mod, though not as big as some I have played, and requires allot of the clients computer. again as Wolfpack98 said the mod is mostly run client side and demands very little of the actual server. mostly the server just serves as a link to link the mylutiple client's computers togeather so that you can see each other virtually.
One way that you can limit the lag is to reduce the processed geometry in your effects section of your options menu.