Dunno if these can help in any way to build eOS for more Xiaomi (mediatek-based) devices, but seems interesting:
https://github.com/hipexscape/device_xiaomi_mt6768-common
https://github.com/hipexscape/proprietary_vendor_xiaomi_mt6768-common
Kernels:
https://github.com/search?q=xiaomi+mt6768+kernel&type=repositories&s=updated
Hope that helps.