NEC ECC: Quotations under NEC3 ECC - for subcontracted elements

I have been searching for literature where a detailed explanation of producing a quotation for a compensation event for Option B - ECC contract is used which also includes a portion of subcontracted works.

Can anyone assist?

It has been a while since I last read it but have you tried the Managing Reality series Book 4: Managing Change, by Barry Trebes and Bronwyn Mitchell?

Essentially you use the Shorter Schedule of Cost Components and allocate the cost to the appropriate cost component. Subcontractor’s costs are allocated in the same way as Contractor’s costs and you then apply the subcontracted fee percentage to the components which are Subcontractor’s costs and the direct fee percentage to other (Contractor) costs.

Under Option B the cost of preparing quotations is not treated as Defined Cost.