I am not forgetting about the MHRA guidance on biosimilars, I see nothing at all relevant in it.
Biosimilars do not have to prove efficacy, only "sameness" as the approved biologic. Direct needs to run trials to prove efficacy. So will -L in other indications.
Not certain that advancement applies to what you are arguing regarding Direct (potential) approval speed. They are tangentially related, but the primary relationship for Direct will be efficacy in its own right (as opposed to proving biosimilarity to DCVax-l)
On the other hand, DCVax-l automated (potential) manufacturing certification could be sped up by proving biosimilarity to manual product without the encumbrance of human/animal bridge efficacy studies.