Honor 7A and Honor 7C also has the same CPU MSM8937 but no twrp for them.
Honor 6A has older system, EMUI 5.1 and CPU MSM8937.
I tried to port Honor 6A's TWRP to stock recovery of Y7 Prime 2018..
It boots, but extremely unstable and reboots to recovery after 2 sec. You can not bypass recovery-loop, only way is to reflash original recovery_ramdisk in bootloader mode.
If someone can help, to make stable twrp, link is https://www.androidfilehost.com/?w=files&flid=285727
Use fastboot flash recovery_ramdisk rec_ramdisk_honor6a.img
and fastboot reboot
to reboot to system. Then reboot to recovery using some app or adb command... Be sure that you already make backup of stock recovery_ramdisk for re-flashing / unbricking.
update: problem is probably in many *.rc files in /recovery_ramdisk but also in symlinked files from /vendor