Requiring everyone to place three telephone calls because email / IMs are ignored is objectively bad behavior. The drivers may be varied but* the outcome remain

Requiring everyone to place three telephone calls because email / IMs are ignored is objectively bad behavior. The drivers may be varied but* the outcome remains the same. Assuming OP's claim is an accurate retelling, this person serves as a delivery roadblock and is either incompetent or lazy at managing their time and resources. Ergo, there is clear need for the OPs organization to either realign the roadblocker's priorities or to build out the functionality themselves. Roadblocker's intent to do good is immaterial -- their actions and tactics are resulting in poor outcomes for those that are required to partner with them.