So, HoG ain't playin' nice. Magic button does nothing, when I selected Beta for Taimen.
I had to get this flashed so I could get it set up and head to bed. So, I extracted the .ZIP and used flash_all - but with a twist.
For every fastboot flash command, I added the argument --slot all - so all flashing would be to both slots where applicable.
Sure enough, it worked like a champ.
Microsoft Windows [Version 10.0.18855.1000]
(c) 2018 Microsoft Corporation. All rights reserved.
D:\Users\{userlogin}\AppData\Roaming\HouseOfGoogle\IMAGES\taimen\taimen-qpp1.190205.018.b4>fastboot devices
710KPMZ0254299 fastboot
D:\Users\{userlogin}\AppData\Roaming\HouseOfGoogle\IMAGES\taimen\taimen-qpp1.190205.018.b4>PATH=%PATH%;"%SYSTEMROOT%\System32"
D:\Users\{userlogin}\AppData\Roaming\HouseOfGoogle\IMAGES\taimen\taimen-qpp1.190205.018.b4>fastboot flash bootloader bootloader-taimen-tmz20o.img --slot all
Sending 'bootloader_a' (36356 KB) OKAY [ 0.255s]
Writing 'bootloader_a' OKAY [ 0.487s]
Sending 'bootloader_b' (36356 KB) OKAY [ 0.264s]
Writing 'bootloader_b' OKAY [ 0.271s]
Finished. Total time: 1.292s
D:\Users\{userlogin}\AppData\Roaming\HouseOfGoogle\IMAGES\taimen\taimen-qpp1.190205.018.b4>fastboot reboot-bootloader
rebooting into bootloader OKAY [ 0.000s]
Finished. Total time: 0.000s
D:\Users\{userlogin}\AppData\Roaming\HouseOfGoogle\IMAGES\taimen\taimen-qpp1.190205.018.b4>ping -n 5 127.0.0.1 >nul
D:\Users\{userlogin}\AppData\Roaming\HouseOfGoogle\IMAGES\taimen\taimen-qpp1.190205.018.b4>fastboot flash radio radio-taimen-g8998-00008-1901230130.img --slot all
Sending 'radio_a' (60372 KB) OKAY [ 0.418s]
Writing 'radio_a' OKAY [ 1.509s]
Sending 'radio_b' (60372 KB) OKAY [ 0.418s]
Writing 'radio_b' OKAY [ 1.440s]
Finished. Total time: 3.785s
D:\Users\{userlogin}\AppData\Roaming\HouseOfGoogle\IMAGES\taimen\taimen-qpp1.190205.018.b4>fastboot reboot-bootloader
rebooting into bootloader OKAY [ 0.016s]
Finished. Total time: 0.016s
D:\Users\{userlogin}\AppData\Roaming\HouseOfGoogle\IMAGES\taimen\taimen-qpp1.190205.018.b4>ping -n 5 127.0.0.1 >nul
D:\Users\{userlogin}\AppData\Roaming\HouseOfGoogle\IMAGES\taimen\taimen-qpp1.190205.018.b4>fastboot -w --slot all update image-taimen-qpp1.190205.018.b4.zip
Warning: slot set to 'all'. Secondary slots will not be flashed.
extracting android-info.txt (0 MB) to RAM...
--------------------------------------------
Bootloader Version...: TMZ20o
Baseband Version.....: g8998-00008-1901230130
Serial Number........: 710KPMZ0254299
--------------------------------------------
Checking product OKAY [ 0.000s]
Checking version-bootloader OKAY [ 0.015s]
Checking version-baseband OKAY [ 0.000s]
extracting boot.img (40 MB) to disk... took 0.179s
archive does not contain 'boot.sig'
archive does not contain 'boot.sig'
extracting dtbo.img (8 MB) to disk... took 0.022s
archive does not contain 'dtbo.sig'
archive does not contain 'dtbo.sig'
archive does not contain 'dt.img'
archive does not contain 'odm.img'
archive does not contain 'product.img'
archive does not contain 'product-services.img'
archive does not contain 'recovery.img'
archive does not contain 'super.img'
extracting system.img (2374 MB) to disk... took 12.533s
extracting vbmeta.img (0 MB) to disk... took 0.000s
archive does not contain 'vbmeta.sig'
archive does not contain 'vbmeta.sig'
extracting vendor.img (344 MB) to disk... took 2.012s
mke2fs 1.44.3 (10-July-2018)
Creating filesystem with 29518843 4k blocks and 7380992 inodes
Filesystem UUID: 8f05d8fe-4ae0-11e9-8361-6183570a530b
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872
Allocating group tables: done
Writing inode tables: done
Creating journal (131072 blocks): done
Writing superblocks and filesystem accounting information: done
Sending 'boot_a' (40960 KB) OKAY [ 0.286s]
Writing 'boot_a' OKAY [ 0.534s]
Sending 'boot_b' (40960 KB) OKAY [ 0.286s]
Writing 'boot_b' OKAY [ 1.912s]
Sending 'dtbo_a' (8192 KB) OKAY [ 0.053s]
Writing 'dtbo_a' OKAY [ 0.380s]
Sending 'dtbo_b' (8192 KB) OKAY [ 0.054s]
Writing 'dtbo_b' OKAY [ 0.402s]
Sending 'vbmeta_a' (4 KB) OKAY [ 0.000s]
Writing 'vbmeta_a' OKAY [ 0.000s]
Sending 'vbmeta_b' (4 KB) OKAY [ 0.016s]
Writing 'vbmeta_b' OKAY [ 0.000s]
Setting current slot to 'a' OKAY [ 0.100s]
Erasing 'userdata' OKAY [ 6.438s]
Sending 'userdata' (4672 KB) OKAY [ 0.047s]
Writing 'userdata' OKAY [ 0.107s]
Rebooting
Finished. Total time: 25.988s
D:\Users\{userlogin}\AppData\Roaming\HouseOfGoogle\IMAGES\taimen\taimen-qpp1.190205.018.b4>
Any sort of log stored somewhere that I can send you to figure out why it just hung on magic?