Use of Indemnity to Principal Clauses in lieu of Insurance Policies in Joint Names

Clause 83.3 of the NEC4 ECC Contract/Subcontract/Short Subcontract requires that “…the insurances in the Insurance Table are in the joint names of the Parties except…”.

A subcontractor has offered that instead of this, their current insurance includes for an “Indemnity to Principal” clause, and has asked that a Z clause be incorporated to allow this. On the face of it, this appears to be intended to act much like a Joint Names insurance would, although it is difficult to know exactly how this would work in practice.

Does anyone have any experience with an Indemnity to Principal clause, or able to offer an opinion if they should be accepted in lieu of a jointly named policy?

@Barry_Trebes @chriscorr @stevencevans do you have an opinion on this?