on deprecation the remaining valid lifetime is set to two hours (even if the timer was less before), so the lifetime will grow on deprecation
RFC 4862 want's the remainig valid lifetime to be set to two hours (7200s), radvd uses 7203s - this has no practical effect but some protocol testers like CDRouter are complaining if the timer is less than 7200s (so radvd based devices will be red - not RFC compliant)
two issues: