I believe there is a way to solve this scaew you could split the game in two parts who uses mod could use in a previous version than you updated
how much players loyal to the original game enjoy the original version that you are updating with graphics and other benefits so those who like real competition use the s3 pro mode
others who like clandestine mode would use mod mode so you would have time to work on new projects for the original lfs
it's just an idea you can use from what i'm trying to say
in the matter of servers, you can do the same to create the mod server
as long as players continue to buy the license to have this benefit
this idea came from aseto corsa, which uses two platforms one asseto corsa,,, and asseto corsa competizione
are separate games