On the EMS side, they now have all the incentives now to "pump up" the numbers of NREs. What might well have been a healthy $500k NRE might suddenly be listed as $1.5M, including many service items that were not necessary for a startup.
On the startup side, it will try to use a high valuation to bring down the dilution but the EMS might never agree with its valuation since most early-stage startups are pre-revenue. EMS's thinking is all about P&L numbers. Without revenue numbers, it could not even "pretend to" do a proper valuation.
This debate could drag on for months. The next thing you know, product shipments are delayed, cash burns out, other VC investors walk away and a promising startup dies for wasting too much time on this wrong debate for no good reason.