Hello guys! I'm owner of Xperia E3 and with a little of research and the help of some developers I have been able to compile LineageOS 14.1. Since tianchi uses Snapdragon 400 as my device, perhaps I can help you bringing life to this.
Can anyone tell me what you have done?
EDIT: I have done a basic device tree for LineageOS 14.1:
https://github.com/rmnhg/device-sony-tianchi
We need a new kernel v3.4.0 and vendor files
For kernel we could try to port device-tree and some drivers (don't expect it fully working in the first attempt)