Unlimited entitlement:

Only those products can be given as unlimited entitlement whose usage types are generated by resourceType of the product bundle. Please check specific connector document to check which usage types are generated by a specific resourceType. Unlimited entitlements are always subscription scoped and cannot be used across subscriptions of a user.

Limited entitlement and resource isolation is true:

Entitlements are user scoped and all entitlements of a specific product are added up for a user.

Limited entitlement and resource isolation is false:

Entitlements are account scoped and all entitlements of a specific product are added up for an account.