Hey Steve,
The only place where we mention kernel parameters is
"For a list of supported kernel parameters, see the Red Hat Enterprise Linux — Hypervisor Deployment Guide."
I'm thinking this should be moved to Hypervisor Deployment Guide?
Discussed with mburns, at this time the activation key field is not exposed via the TUI. Bug # 867042 (from which this bug was cloned, refer to the description) already tracks the need for the Hypervisor Deployment Guide to be updated with the parameter based approach.