Tenho quase certeza de que não pode ser resolvido por software, mas aqui estão as considerações, caso tenham alguma ideia ou parecer, seria de extremo alívio:

Consigo acessar pelo fastboot (identifica o dispositivo pelo comando "fastboot devices");
Não consigo flashar roms de fábrica (dá erros relacionados a bootloader ou partições em todos os comandos);
Não consigo fazer o blankflash (não identifica o dispositivo).

Modelo XT1792.

Aqui está o log do "fastboot getvar all":

(bootloader) version: 0.5
(bootloader) version-bootloader: moto-msm8937-BC.12(*)
(bootloader) product: montana
(bootloader) board: montana
(bootloader) secure: yes
(bootloader) hwrev: P3
(bootloader) radio: 3
(bootloader) storage-type: emmc
(bootloader) emmc: 32GB SAMSUNG QX13MB RV=08 PV=07 FV=0000000000000007
(bootloader) ram: 2GB SAMSUNG LP3 DIE=8Gb M5=01 M6=05 M7=00 M8=1F
(bootloader) cpu: MSM8937
(bootloader) serialno: 2e1801a1
(bootloader) cid: 0xDEAD
(bootloader) channelid: 0x00
(bootloader) uid: E37B906C00000000000000000000
(bootloader) securestate: oem_locked
(bootloader) iswarrantyvoid: n/a
(bootloader) max-download-size: 535822336
(bootloader) reason: Fall-through from normal boot mode
(bootloader) imei: 000000000000000
(bootloader) meid:
(bootloader) date: 01-01-1970
(bootloader) sku: 000000000000000
(bootloader) carrier_sku:
(bootloader) battid:
(bootloader) iccid:
(bootloader) cust_md5:
(bootloader) max-sparse-size: 268435456
(bootloader) current-time:
(bootloader) ro.build.fingerprint:
(bootloader) poweroffalarm: 0
(bootloader) ro.build.version.full:
(bootloader) ro.build.version.qcom:
(bootloader) version-baseband:
(bootloader) kernel.version:
(bootloader) sbl1.git: sbl1.git
(bootloader) rpm.git: rpm.git
(bootloader) tz.git: tz.git
(bootloader) devcfg.git: devcfg.git
(bootloader) keymaster.git: keymaster.git
(bootloader) cmnlib.git: cmnlib.git
(bootloader) cmnlib64.git: cmnlib64.git
(bootloader) prov.git: prov.git
(bootloader) aboot.git: git=MBM-NG-VBC.12-0-g0b9dae9
(bootloader) frp-state: no protection (err)
(bootloader) ro.carrier:
(bootloader) current-slot:
(bootloader) slot-suffixes: _a
(bootloader) slot-count: 1
(bootloader) slot-successful:_a: INVALID
(bootloader) slot-successful:_b: INVALID
(bootloader) slot-bootable:_a: INVALID
(bootloader) slot-bootable:_b: INVALID
(bootloader) slot-retry-count:_a: unknown
(bootloader) slot-retry-count:_b: unknown
all: listed above
Finished. Total time: 0.069s

Agradeço, desde já