I think a bit of clarification is needed here.
Because the engine isn't coming with a 'Fitted in service' warranty, does not mean that the engine is inferior, or the work involved to fit it - substandard.
It is normal practice (and I have said this many times when answering threads on the forum), that a component paid for 100% by warranty only is covered by the balance of the vejicle's warranty.
The reason being; it is, in effect a 'trade sale' and is such exempt from much of the legislation pertaining to consumer law. Warranty is paying for the repair in full, so they (not you), are the customer, in this transaction.
Before you feel like you have 'lost-out', bear in mind the
Renault Customer Services
are there to deal with vehicles which are out of warranty, and they will apply goodwill as required, if there is any issue with the engine.
I worked as a manager in such a department for Ford Motor Company, and I can assure you, that this is standard industry practice.