> This is necessary as (a) the 5h limit allows us to smoothen the load on our compute, allowing to keep the plan generous in terms of weekly usage

Seems fair, but then maybe the 5h usage should also drain slower during off-peak hours? Perhaps it already does.

> and (b) users on the Plus plan are relatively casual and new users, but then also just accidentally eat through their whole weeks usage and then are confused, making it not a great experience.

Wouldn't this one be fixed by making the 5h limit a guardrail you can opt out of? If so, then this doesn't work as justification for a mandatory limit.