@tlaurion @mkukri tl;dr - we already discussed yoru concerns in #libreboot earlier. As Mate said, the upstreaming will be done at a later date when he feels like it. We're not in any rush . You just have to wait.
By the way: there's also the S model. T480s. your initial patch for Heads seemed to only focus on T480, but there's also T480s. so that ifdef should also handle T480s.
Perhaps a better way is this:
Define HAVE_H8S_EC or something, on the other thinkpads. Because T480 doesn't have it.