Ideally, a platform team should give you reliable, self-service components to build upon, like databases, caches, rate-limiters, api-gateways, etc.
If they're framework-ish, they're mandating you build your app in exactly their preferred way in order to receive the benefits.
An important realization in my opinion is that a platform team is just another development team. They should consider their platform as a product and the developers as their customers. To minimize any downtime they should use the typical mechanisms that developers are also using: automated tests, pair programming, rolling out changes to test environments first, etc.
When done right a platform team should basically not be noticed except that the tooling, developer experience and overall reliability of a system goes up.
In memories!