Bought unlocked from Carphone Warehouse, selling my mint Pixel 3a XL in black. Also bought the official fabric case from the Google store which is worth £40. The phone comes with an offer to allow you to redeem and get a free Acer Chromebook worth £199.
New TWRP 188.8.131.52 but not tested (no more Y300).
If anyone what to try, beware - backup your phone, be ready to flash working recovery via download mode, if can not boot to system!
TWRP-184.108.40.206.img built with omni-5.1 branch, because missing omnirom/system/core 4.4 branch in repo.
TWRP-220.127.116.11.img build with omni-5.1 and mixed with omni-4.4.