You're doing the right thing, SEL, and smart to do this now whilst things are good. He's been very lucky to have 15 trouble-free years, but imagine if he was ill or injured, especially now he's aging (and borderline laminitic like you say!). Can't imagine he'd allow anyone near him if he was in pain and frightened, or that he'd make life easy if he developed a condition that needed regular medication etc, and none of those situations would be a pleasant end for him.