[General Questions and Answers] tom353:
I have extracted everything I could with mtk client:

-rwxrwxrwx 1 user user 40M Aug 9 16:15 boot_a.bin

-rwxrwxrwx 1 user user 40M Aug 9 16:17 boot_b.bin

-rwxrwxrwx 1 user user 1.0M Aug 9 16:13 boot_para.bin

-rwxrwxrwx 1 user user 8.0M Aug 9 16:15 dtbo_a.bin

-rwxrwxrwx 1 user user 8.0M Aug 9 16:17 dtbo_b.bin

-rwxrwxrwx 1 user user 20M Aug 9 16:41 elabel.bin

-rwxrwxrwx 1 user user 20M Aug 9 16:13 expdb.bin

-rwxrwxrwx 1 user user 16M Aug 9 17:42 flashinfo.bin

-rwxrwxrwx 1 user user 1.0M Aug 9 16:13 frp.bin

-rwxrwxrwx 1 user user 17K Aug 9 16:13 gpt.bin

-rwxrwxrwx 1 user user 16K Aug 9 16:13 gpt_backup.bin

-rwxrwxrwx 1 user user 16M Aug 9 16:15 gz_a.bin

-rwxrwxrwx 1 user user 16M Aug 9 16:16 gz_b.bin

-rwxrwxrwx 1 user user 2.0M Aug 9 16:15 lk_a.bin

-rwxrwxrwx 1 user user 2.0M Aug 9 16:16 lk_b.bin

-rwxrwxrwx 1 user user 11M Aug 9 16:14 logo.bin

-rwxrwxrwx 1 user user 16M Aug 9 16:15 md1dsp_a.bin

-rwxrwxrwx 1 user user 16M Aug 9 16:16 md1dsp_b.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:14 md1img_a.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:15 md1img_b.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:14 md2img_a.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:16 md2img_b.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:14 md4img_a.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:16 md4img_b.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:14 md5img_a.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:16 md5img_b.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:14 md6img_a.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:16 md6img_b.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:15 md7img_a.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:16 md7img_b.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:15 md8img_a.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:16 md8img_b.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:15 md9img_a.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:16 md9img_b.bin

-rwxrwxrwx 1 user user 23M Aug 9 16:41 md_udc.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:13 metadata.bin

-rwxrwxrwx 1 user user 32M Aug 9 16:13 nvcfg.bin

-rwxrwxrwx 1 user user 64M Aug 9 16:13 nvdata.bin

-rwxrwxrwx 1 user user 64M Aug 9 16:14 nvram.bin

-rwxrwxrwx 1 user user 518M Aug 9 16:43 oem_reserve.bin

-rwxrwxrwx 1 user user 43M Aug 9 17:42 otp.bin

-rwxrwxrwx 1 user user 512K Aug 9 16:13 para.bin

-rwxrwxrwx 1 user user 48M Aug 9 16:14 persist.bin

-rwxrwxrwx 1 user user 3.0M Aug 9 16:14 proinfo.bin

-rwxrwxrwx 1 user user 8.0M Aug 9 16:13 protect1.bin

-rwxrwxrwx 1 user user 9.5M Aug 9 16:13 protect2.bin

-rwxrwxrwx 1 user user 1.0M Aug 9 16:15 scp_a.bin

-rwxrwxrwx 1 user user 1.0M Aug 9 16:16 scp_b.bin

-rwxrwxrwx 1 user user 2.0M Aug 9 16:14 sec1.bin

-rwxrwxrwx 1 user user 8.0M Aug 9 16:13 seccfg.bin

-rwxrwxrwx 1 user user 1.0M Aug 9 16:15 spmfw_a.bin

-rwxrwxrwx 1 user user 1.0M Aug 9 16:16 spmfw_b.bin

-rwxrwxrwx 1 user user 1.0M Aug 9 16:15 sspm_a.bin

-rwxrwxrwx 1 user user 1.0M Aug 9 16:16 sspm_b.bin

-rwxrwxrwx 1 user user 8.0G Aug 9 16:41 super.bin

-rwxrwxrwx 1 user user 5.0M Aug 9 16:15 tee_a.bin

-rwxrwxrwx 1 user user 11M Aug 9 16:17 tee_b.bin

-rwxrwxrwx 1 user user 20G Aug 9 17:41 userdata.bin

-rwxrwxrwx 1 user user 8.0M Aug 9 16:15 vbmeta_a.bin

-rwxrwxrwx 1 user user 8.0M Aug 9 16:41 vbmeta_b.bin

-rwxrwxrwx 1 user user 8.0M Aug 9 16:15 vbmeta_system_a.bin

-rwxrwxrwx 1 user user 8.0M Aug 9 16:41 vbmeta_system_b.bin

-rwxrwxrwx 1 user user 14M Aug 9 16:15 vbmeta_vendor_a.bin

-rwxrwxrwx 1 user user 8.0M Aug 9 16:41 vbmeta_vendor_b.bin

-rwxrwxrwx 1 user user 30G Aug 10 21:48 user.bin (that's the entire flash)

-rwxrwxrwx 1 user user 252K Aug 11 09:25 preloader_malta.bin

-rwxrwxrwx 1 user user 4.0M Aug 10 20:13 boot1.bin

-rwxrwxrwx 1 user user 4.0M Aug 10 20:14 boot2.bin

-rwxrwxrwx 1 user user 4.0M Aug 10 20:18 rpmb.bin

if I erase userdata with mtk client, the device boots. Also, userdata.bin can be mounted, so I'm going to try deleting data from it to try and narrow it down (every iteration takes several hours to flash).