Specifying max shutdown delay seconds for services with disks

I have a web service that uses a disk. When I created the service through the API (actually the Pulumi Render provider which uses the REST API) the setting for maxShutdownDelaySeconds defaulted to 30s as mentioned in the API docs too. But now when I try to update the service via the PATCH by sending the entire request body, the API server is rejecting the request because maxShutdownDelaySeconds has a value and services with disks cannot have a value for that setting. But if that’s true, then how did the service get created with the default value? Maybe the API should accept a value of 0 (and also default to that) for services with disks instead?

Also side note why can’t I set the max shutdown delay seconds for services with disks? Feels like some infra limitation that prevents us from using that setting.