The 5 hour conversion comes from the days when RAA was only low speed (low inertia)
I reckon it is still valid even for LSAs, much lower inertia than, say, a C172. Many cases of bent aircraft in the USA by pilots thinking that because they can fly a big C172 (and 747) that didn't need conversion training for a 600KG aircraft...
My instructor was converting a SAAB driver; took a while not to get him to flare too high.