[Honor 9 Lite  ROMs, Kernels, Recoveries, & Other D] EPT-3:
Following a previous post of mine (https://xdaforums.com/t/tool-huawei-multi-tool-v8-by-team-mt.3523923/post-87608941) , it seems to me that ALF has a deep knowledge of such devices. This is why I reply here, first to (publicly) knowledge its knowledge (already advanced mine) and second, if I have a chance for a specific explanation to my problem.

Next to my that post, I did manage to UNLOCK the BootLoader!!!

TomatoNV for free!!!

Huawei Honor 9 Lite, with a replaced mainboard (before LLD-L31, now LLD-L21)

[ (LLD-L21 8.0.0.122(C636), vendorcountry: hw/spcseas (=ASIA), (bootloader) :LLD-AL00 8.0.0.189(C00),

CUSTOM_VERSION still FAILED (remote: 'Read oeminfo failed!'), SYSTEM_VERSION (bootloader) :LLD-AL00 8.0.0.189(C00) ]

Now, though I can fastboot flash partitions (Huawei UPDATE.APP extractor/ I get the needed .img files etc.) both dload mode with SD CARD/fat32 and also by using older HiSuites mode, always FAIL...

e.g.

TRY no 1:

(With fastboot in COLDBOOT_0 or COLDBOOT_16 states/the "best" states I could get...:)

(With the Service (??) ROM used: LLD-L31 hw eu HLRCF Leland-L31A 9.1.0.149_C432E6R1P4T8_FW-9.0.0 r3 EMUI9.1.0 05015ADR_androidhost.ru, though I am LLD-L21 now... it is the only one that succeeds SYSTEM flash...)

fastboot flash cust CUST.img

fastboot flash cache CACHE.img

fastboot flash recovery_ramdisk RECOVERY_RAMDIS.img

fastboot flash userdata USERDATA.img

fastboot flash kernel KERNEL.img

fastboot flash vendor VENDOR.img

fastboot flash system SYSTEM.img

RESULT: Everything OK, (with various recovery_ramdisk Recoveries used, both Custom & TWRPs) but the device returns always to the "Please restore system again" Error, AND

Error!

Func NO: 11 (recovery image)

Error NO: 2 (load failed!)

Try no 2:

Then, I tried to flash erecovery (Recovery2 I guess...).

(Now, with a fastboot at state COLDBOOT 0 and the same as previous Service (??) ROM used, I get:)

fastboot flash erecovery_ramdisk ERECOVERY_RAMDI.img ---> OK!

fastboot flash erecovery_kernel ERECOVERY_KERNE.img ---> OK!

fastboot flash erecovery_vbmet ERECOVERY_VBMET.img ---> FAILED!

fastboot flash erecovery_vendor ERECOVERY_VENDO.img ---> OK!

The size of the vbmet .img to be flashed is very small (76.4 kB) in contrast with the other 3 images (some MBs).

So, in order to avoid "bothering" you further with details, I guess that my problem is the always-retutn to the same error to boot into recovery/System and the best I can get is to get a fastboot COLDBOOT state (by using the vol- & power buttons) to get into fastboot...

Which possibly means EITHER a hardware problem (the battery is brand-new! However, when I disconnect PC-USB from device it directly powers off!) OR the device denies to boot into somewhere (Recovery or eRecovery or System)...

I can still contact Huawei in my country for a software update try OR even order a new mainboard from China.

But I decided to fight for my device!

Because also, a Mediapad M3 BTV-D09 tablet of mine is still waiting 5 years for its "jailbreak" UNLOCKING!

Anyway, thanks to xda, ALF & others, I already advanced my (poor) technical knowledge!

Thank you for reading my post.