After OPPO/OnePlus merger, things went downhill really fast. IIRC, OPPO did something that ended up alienating some parts of Lineage/ROM developer community in general and the work on supporting newer devices was postponed until couple months ago; also, they've patched up the bootloader relock possibility [0] which was likely good for security considering it was based on some exploit.

0. https://calyxos.org/news/2022/07/06/oneplus-android-12-reloc...