Appointments & Fees: novation, uninsurable terms, and PII protection

You are appointed under a RIBA Standard PSC 2020 by Helios Developments Ltd on a £12 million mixed-use scheme of retail at ground floor and 38 apartments above, procured as a JCT Design and Build 2024. Your appointment was executed under hand at Stage 2 with a net contribution clause limiting your liability to a fair and reasonable share, an aggregate liability cap of £10 million matching your PII, and the standard PSC 2020 standard of care wording at clause 3.1. You were novated to the main contractor, Westcliffe Build Ltd, at the end of Stage 4 using the CIC Novation Agreement Ab Initio 2018. Two months into Stage 5, Westcliffe's solicitors send you a draft "wider" appointment that they wish you to sign in place of the novated PSC. They are aggressive about the timetable: contracts must be executed within three weeks or, they say, Westcliffe will terminate your engagement. The draft they have sent contains four red flag clauses. First, the net contribution clause has been deleted and the appointment includes a joint and several liability provision. Second, clause 4 imposes a "fitness for purpose" duty in respect of the apartments meeting BREEAM Excellent and meeting a specified net operational energy figure. Third, clause 8 requires you to indemnify Westcliffe for any losses arising from the acts, errors, or omissions of your sub-consultants, including the structural engineer you appointed for civil works. Fourth, the liability cap has been raised to £20 million. You email your PII broker. The broker replies the same day in writing: every one of these provisions is excluded from cover under your standard policy. The fitness for purpose obligation in particular will void cover on the entire claim. The broker advises you not to sign in its current form. Westcliffe's commercial director then telephones to say that if the appointment is not signed within ten days they will issue a determination notice and pursue you for the cost of replacing you on the project.