I don't think the original work around would work with Kea becuase how the Jinja is formatted, but expanding on this for Kea specifically, a couple of things that would need to be implemented would be client classes that match have some type of match

Ran across this when trying to get a DHCP relay when doing EVPN, also on an Arista platform

This bug is still present in the latest 1.4 rolling release