@kln_nurv yeah, its xiamoi in general thats not viable anymore, and I don't think any new xiaomi device will be ported. about the poco X3, if it doesn't have an efuse you're best bet is to downgrade to miui 12 with sp flash tool and bootrom bypass, then install a custom payload.bin from an already unlocked phone, i don't have this device but if you want this to still be viable we need a unlocked bootloader dump from a donor phone via sp flash (preferably a full nand dump).
if you get me a full nand dump i can probably create a small bootloader unlock "rom" for you to flash with sp flash.
just be ware that the nand dump if it a full one should not contain these: protect1, protect2, nvcfg, nvdata, nvram because they contain IMEI, bluetooth address/MAC, ect.
protect1/2 are sometimes called L/R instead of 1/2 in the scatter file.