Sounds like a planning policy issue. Ie the company is approved for 120 but have a policy to plan to 90. I don’t imagine you’d need any more fuel for 93 minutes anyway, unless you’re fuel is always driven by the ETOPS requirement?
Our company has 180 approval but the policy is to plan 120 if possible. I wouldn’t be ad how planning beyond 120 minutes against our policy, even though it’s all legal.