If it were me I'd assume the majority of BMC firmware out there from all vendors: 1. Is full of many many exploitable vulnerabilities 2. To the extent they patch holes it will be whack-a-mole because the economics do not permit large investments in software quality. 3. Many server owners will never install a patch anyway.
Unfortunately, Supermicro doesn't use it yet for most of their servers. Probably because they sell an extremely expansive license for their own software so you can use the Redfish API.
If you build own servers that's an option to consider but most off-the-shelf servers are sold with BMC (so you pay for it even if don't want it). May be some low end brands sell servers without BMC but if you are looking for relatively reliable hardware you'll likely get a server with BMC.