Define “consistently”.For sake of argument suppose I was a tenant and my contract obliged me to forward him post. Could my landlord issue a notice to quit for breach of tenant obligations if I failed to do so consistently?
There’s no subjective threshold - you’re either in breach or you’re not.
However, a vague requirement to forward post will always be interpreted against the party that drafted the lease (i.e. the landlord).
Contractual obligations have to be clear.