Sometimes your just need a buffer for a syscall. Newing a buffer is canonical and unique_ptr isn’t free enough to use in the most performance sensitive contexts.
Open up your computer, pull out the bmc, throw it in the garbage. If you are reliant on these things then you are still in a pet-computer world and you’ll benefit greatly by moving to the cattle model. This article has a section on why you need a bmc but doesn’t succeed in advocating for it. It’s another computer inside your main computer with its own set of flaws, bugs, and costs.