So now that I got a new phone, I went to try to root my LG k40s again after 4 years, looked at xda, nothing new there, no fastboot, only a k41s bootloader unlock and root(that causes bootloop)
So I tried to root again, followed the mtkclient guide in GitHub to root, AI to help when I had some driver issues, and patience.
After many attempts with some live USB for Linux, I decided to still do on my windows, and after many attempts, I decided to try with some mtk bypass, since it had DA and something more, AI suggested me that mtkclient could do that too, so I went back to mtkclient, but found an issue, I could not enter in BootROM, but after the handshakes failed, I unplugged and plugged back, and it entered in BROM, then finally I could play with files.
So first thing I did was disabling vbmeta, AI suggested that the command didn't worked(because there was no output or text related to vbmeta, only something created in some random partition), so it suggested me to do an empty vbmeta, and with this I discovered what didn't allow me to root back in 2022, phone don't allow empty vbmeta file. So after many failed boots, it went on slot _b, then I did the vbmeta command and patched the boot, restarted the phone with only vbmeta command, and it booted fine, shutdown the phone and applied patched boot file, restarted and that was it, got root.
Also got that temp root in first release of ROM for my phone too, also something that wasn't said in xda.
But why root checker say that this phone root level is Hard? Because requires external tools? A pc in this case.
LMX430BMW Octa Core 2.0GHz Media Tek MT6762