Thanks. I've done a bit more digging since my initial post and I'm still a bit confused. Maybe I didn't state the conditions properly.
In looking at Rev-Rul 2004-13, IRC 416(g)(4)(H) and IRC 401(k)(12) it would appear that if you have a safe-harbor 401(k) plan that gives the safe-harbor contribution to all NHCEs (no NHCE exclusions), but does not give the S-H to any HCE, and that is your only employer contribution for the year, then your plan is deemed "not top-heavy" under IRC 416(g)(4)(H) for that year and you do not have to give the "top up" T-H minimum to the non-key HCEs who are ineligible for the S-H contribuion becuase your plan statifies all requirements of IRC 401(k)(12)©. Assume all notices proper and timely.
Am I reading the code wrong, or is it just wishful thinking on my part trying to save the client from making an addition contribution that they don't want to make?