I’m going to suggest it’s not true. Dealers have allocated numbers and register online. It took my dealer 5 minutes a few weeks ago. I doubt if the time it takes DVLA to issue the paperwork matters.
I think the conversation companies are not main dealers so may have to pass the documentation over to in this case to Renault .
Other extra hoops is the vehicle needs a Individual Vehicle Approval test, this is we’re they check the wheelchair tracking for strength, so more red tape paperwork to be signed off by DVLA ? .