Running an OS with 2016 security patches is a risk. Custom ROM developers often backport security fixes to older hardware.
Unlike Qualcomm’s EDL mode, MediaTek uses and BROM (BootROM) mode. This makes the MT6735 nearly unbrickable if you know what you are doing, but also more dangerous if you mix up preloader files. mt6735 custom rom
[ROM] New rom for Mt6735 (x64) 3.10.65+ kernel NAME - Facebook Running an OS with 2016 security patches is a risk