The regular Tontine Trust is for parents that want to avoid the risking of running out of money in old age and becoming a financial burden on their children.
The Tontine Trust Fund is for parents that want to set aside an inheritance for their spouse or children now which they can configure to start paying the child a monthly income for the rest of their life starting at age X. This reduces the concern of parents that they will pass on a chunk of the inheritance to children that will 'blow the money' instead of making it last them for life.
Also, FYI: a) Research from the insurance industry indicates that tontiners/annuitants spend double what they would without having a lifetime income, thereby enabling a better quality of life in retirement. b) The Swiss Federal Institute of Technology, alma mater of Einstein and 28 other Nobel Prize Winners, has produced research showing that a retirees pension wealth is enhanced by 87% with zero added risk upon moving their savings into a Tontine, indicating that the gain is not 'marginal'.
All in all, the Tontine enables you to save a little less yet still spend more.