Hm, "Enhanced Learning" is a bit unclear as well. I think it means per end-of-scenario improvement session. That could be too generous as I frequently allow improvement opportunities within a scenario. For instance, if a sea voyage is called for, that's a couple of months in which they can train and practice and spent IRs. A campaign of several months of gaming might be just one "scenario" as well, if it's a long and complex plot. I'm wary of being too arbitrary in declaring when the bonuses can be used.