The SM-T280 uses a Spreadtrum (Unisoc) SC8830 processor , not a Qualcomm or Exynos. This makes custom ROM development extremely rare. There is NO fully working LineageOS, Resurrection Remix, or Android 8+ ROM for this tablet. Most “custom ROMs” available are just modified stock firmwares.
Before flashing, you must ensure your tablet is ready to avoid "bricking" the device. samsung galaxy tab a6 smt280 custom rom verified
I have been running the on my SM-T280 for 12 months. Here is my honest verdict: The SM-T280 uses a Spreadtrum (Unisoc) SC8830 processor