I am going to buy the 5026Ti-BTRF, and I had the following question to which I could not answer. “Is built-in raid controller manageable from Linux? I'm concerned about monitoring, can I get status, failed drive warning, etc. inside Linux or will I be forced to look through IPMI only?”
In BIOS, you can choose Adaptec as RAID code base and use the driver from: https://www.supermicro.com/wdl/driver/SATA/Adaptec_PCH/Linux/17717/
These are the OS that have drivers available and you can install ASM store-man
https://www.supermicro.com/wdl/driver/Adaptec_Storage_Management/ for RAID management status.