Please Do Tell More
As a very new owner (one month ago), I am interested in this discussion as to "how you handle the end of charter and also how well your yacht is cared for during its charter period". I guess I'm not aware about the impact I can/may have on this matter. BTW, I also became a member of sunsailowners.com. The fee for 4.5 years was very reasonable. However, I don't see any discussion/advice on that site either that answers your intriguing assertion.
Jim ("Anatolya", BVI)