I assume you are referring to the Engineering and Construction Subcontract (ECS) rather than the Engineering and Construction Short Contract (ECSC).
Although the W Options are perceived to be optional, the intention is that they are not and one of these is chosen. In NEC(1) and NEC2 the dispute resolution procedure was part of the conditions of contract at core clause 9.
If the contract data doesn't state a W option then none would apply, regardless of what was in the main ECC contract., as they are discrete contracts. In this instance you would be required to refer any disputed matter to the applicable legal process which applies in the jurisdiction under which the contract is subject to.
Although the W Options are perceived to be optional, the intention is that they are not and one of these is chosen. In NEC(1) and NEC2 the dispute resolution procedure was part of the conditions of contract at core clause 9.
If the contract data doesn't state a W option then none would apply, regardless of what was in the main ECC contract., as they are discrete contracts. In this instance you would be required to refer any disputed matter to the applicable legal process which applies in the jurisdiction under which the contract is subject to.