[General Questions and Answers] MattyNice:
Okay. I've been trying to do this forever and I'm finally at my wit's end. My phone is a-only, treble supported. There aren't any official custom recoveries for this model, so I've been trying to install a GSI from fastboot. (unofficial TWRP has BIG /data issue). So, i try to do it like this:

While in

FASTBOOT

, not bootloader

verity first with 'fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img' (stock vbmeta)

Wipe with 'fastboot -w'

Delete product partition with 'fastboot delete-logical-partition product'

Flash GSI to system with ' fastboot flash --u system system-arm64-aonly-gapps-su.img'

Also tried in bootloader and same result.

Everything passes, but goes in boot loop to bootloader.

HEEEEEEEEEEEEEEEEEELLLLLLLLLLLLP

(heres the last log and getvar from stock recovery)

C:\Users\treys\AppData\Local\Android\Sdk\platform-tools>fastboot -w

Erasing 'userdata' OKAY [ 4.025s]

mke2fs 1.45.4 (23-Sep-2019)

Creating filesystem with 14137083 4k blocks and 3538944 inodes

Filesystem UUID: 8522e162-392a-11eb-ae1d-7f68c0091b00

Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,

4096000, 7962624, 11239424

Allocating group tables: done

Writing inode tables: done

Creating journal (65536 blocks): done

Writing superblocks and filesystem accounting information: done

Sending 'userdata' (316 KB) OKAY [ 0.023s]

Writing 'userdata' OKAY [ 0.158s]

Erasing 'cache' OKAY [ 0.038s]

mke2fs 1.45.4 (23-Sep-2019)

Creating filesystem with 110592 4k blocks and 110592 inodes

Filesystem UUID: 8575a9ba-392a-11eb-953b-3bd515caf320

Superblock backups stored on blocks:

32768, 98304

Allocating group tables: done

Writing inode tables: done

Creating journal (4096 blocks): done

Writing superblocks and filesystem accounting information: done

Sending 'cache' (68 KB) OKAY [ 0.017s]

Writing 'cache' OKAY [ 0.060s]

Erasing 'metadata' OKAY [ 0.012s]

Erase successful, but not automatically formatting.

File system type raw data not supported.

Finished. Total time: 4.917s

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------C:\Users\treys\AppData\Local\Android\Sdk\platform-tools>fastboot getvar all

(bootloader) battery-soc-ok:yes

(bootloader) battery-voltage:0

(bootloader) off-mode-charge:0

(bootloader) is-userspace:yes

(bootloader) partition-size:para:0x80000

(bootloader) partition-size:metadata:0x2000000

(bootloader) partition-size:userdata:0xD7B7FBE00

(bootloader) partition-size:super:0xD5800000

(bootloader) partition-size:md_udc:0x1800000

(bootloader) partition-size:boot:0x2000000

(bootloader) partition-size:system:0xAED7B000

(bootloader) partition-size:vendor:0x233E3000

(bootloader) super-partition-name:super

(bootloader) partition-type:para:raw

(bootloader) partition-type:metadata:raw

(bootloader) partition-type:userdata:raw

(bootloader) partition-type:mmcblk0:raw

(bootloader) partition-type:super:raw

(bootloader) partition-type:md_udc:raw

(bootloader) partition-type:boot:raw

(bootloader) partition-type:system:raw

(bootloader) partition-type:vendor:raw

(bootloader) has-slot:para:no

(bootloader) has-slot:metadata:no

(bootloader) has-slot:userdata:no

(bootloader) has-slot:mmcblk0:no

(bootloader) has-slot:super:no

(bootloader) has-slot:md_udc:no

(bootloader) has-slot:boot:no

(bootloader) has-slot:system:no

(bootloader) has-slot:vendor:no

(bootloader) max-download-size:0x10000000

(bootloader) version-baseband:

(bootloader) slot-count:0

(bootloader) is-logical:para:no

(bootloader) is-logical:metadata:no

(bootloader) is-logical:userdata:no

(bootloader) is-logical:mmcblk0:no

(bootloader) is-logical:super:no

(bootloader) is-logical:md_udc:no

(bootloader) is-logical:boot:no

(bootloader) is-logical:system:yes

(bootloader) is-logical:vendor:yes

(bootloader) secure:yes

(bootloader) variant:NA

(bootloader) serialno:0123456789ABCDEF

(bootloader) hw-revision:0

(bootloader) product:A7_Pro

(bootloader) current-slot:

(bootloader) version-bootloader:unknown

(bootloader) unlocked:yes

(bootloader) version:0.4

all:

Finished. Total time: 0.786s