Very happy to introduce you to lk2nd for the Idol 3 6045* !
Using the "chaining" ability of bootloader, it's possible to add lk2nd to the boot sequence,
thus installing a working fastboot implementation
/!\ WARNING /!\ might not be appropriate if you use stock ROM, since it will overwrite boot partition and you will need a boot.img to use with fastboot, and not just a boot partition dump/backup !
If you use CyanogenMod/LineageOS/SailfishOS it's okay since you can get the boot.img from the ZIP you flashed already.
Install this lk2nd image to /boot partition using either EMMCdl ou Alcatel Flasher.
Then you will be able to "fastboot flash boot your-ROM-boot.img" so your phone starts as usual, and access fastboot/lk2nd using Power+VolumeDown button.
One advantage over the hybrid-MM-boot-stack hack is that lk2nd supports both old and new boot formats
(uncompressed kernel + dt.img AND compressed kernel + appended DT), also no need to downgrade special partitions.
Interesting command : fastboot oem lk_log; fastboot get_staged /dev/stdout
Thanks to Minecrell for the msm8916-lk2nd project and guidance.
Note to 6039* users : don't install this tool, it is for 6045 only ! It should be easy to add support for 6039 to lk2nd.
Download : lk2nd-idol3-20200410-1.img (md5sum : caaa7e91579ebe76472a01505d498026)
This my own build, which doesn't discriminates on panel model unlike the "official" one which only support r63315 panel at the moment.

XDA:DevDB Information
lk2nd for Idol 3 6045*, Tool/Utility for the Alcatel Onetouch Idol 3
Contributors
vknecht
Source Code: https://github.com/msm8916-mainline/lk2nd/
Version Information
Status: Stable
Created 2020-04-30
Last Updated 2020-04-30
Using the "chaining" ability of bootloader, it's possible to add lk2nd to the boot sequence,
thus installing a working fastboot implementation
/!\ WARNING /!\ might not be appropriate if you use stock ROM, since it will overwrite boot partition and you will need a boot.img to use with fastboot, and not just a boot partition dump/backup !
If you use CyanogenMod/LineageOS/SailfishOS it's okay since you can get the boot.img from the ZIP you flashed already.
Install this lk2nd image to /boot partition using either EMMCdl ou Alcatel Flasher.
Then you will be able to "fastboot flash boot your-ROM-boot.img" so your phone starts as usual, and access fastboot/lk2nd using Power+VolumeDown button.
One advantage over the hybrid-MM-boot-stack hack is that lk2nd supports both old and new boot formats
(uncompressed kernel + dt.img AND compressed kernel + appended DT), also no need to downgrade special partitions.
Interesting command : fastboot oem lk_log; fastboot get_staged /dev/stdout
Thanks to Minecrell for the msm8916-lk2nd project and guidance.
Note to 6039* users : don't install this tool, it is for 6045 only ! It should be easy to add support for 6039 to lk2nd.
Download : lk2nd-idol3-20200410-1.img (md5sum : caaa7e91579ebe76472a01505d498026)
This my own build, which doesn't discriminates on panel model unlike the "official" one which only support r63315 panel at the moment.

XDA:DevDB Information
lk2nd for Idol 3 6045*, Tool/Utility for the Alcatel Onetouch Idol 3
Contributors
vknecht
Source Code: https://github.com/msm8916-mainline/lk2nd/
Version Information
Status: Stable
Created 2020-04-30
Last Updated 2020-04-30
Last edited: