Override DHCP Valid Lifetime

[Diggy]

We're using Kea DHCP server.  The Valid Lifetime set on the Settings tab is sufficient for most of our subnets.  However, there are a couple subnets that require a shorter lease time.

Which Option code, if any, overrides the value set on the Settings tab?  There isn't a code that says "valid lifetime".  The closest I found is "renewal time [58]", but because this is a production router, I cannot do trial and error.  Is "renewal time [58]" the correct code to overrride default valid lifetime?

UPDATE:
The code I mentioned above is for IPv4.  I also need the correct code for IPv6.  Please and thanks.