Servicing Kamasu

Hello. I read on the internet that Kamasu needs servicing after 3-5 years. I've had mine for 4 years. It works fine, there were no hits, no damaging, I took it for a swim but I did not dive with it. Do I need to start thinking of servicing? What are possible issues with mechanism I should worry about? Some say servicing not worth it as it may cost almost the same as the watch, and water resistance might be gone after it.