If follow that where there is a sole trustee of a new-style trust, that trustee should appoint a colleague before selling the land or making some other disposition. What happens if he tries to sell (or mortgage or lease) the trust land acting on his own is a difficult question.
Where the trust land is unregistered title
Apply the doctrine of notice. Where the purchaser from the sole trustee has no notice of the new-style trust, then the rights of the beneficiary (ies) under the trust will be overreached, notwithstanding there being only one trustee.
Where the purchaser has notice of the new-style trust (e.g., under the rule in Hunt v Luck because a beneficiary is occupying the property) he will be bound by the equitable interests under that trust.