I can confirm that the revive via DFU works. It also works over normal USB (instead of usb-c) connector as I used my gf older mac pro late 2015. Be aware that you need at least Mojave 10.14.6+ as the app configurator can't be run/installed on previous versions. There is also a big difference in App configurator 2.10 vs the latest 2.12. On 2.10 (you can find dmg file on internet, but be careful about running untrusted software) you can restore BridgeOS on the chip without wiping the data. In version 2.12 it will wipe all data!
Initially, I tried to restore the system via Virtualbox where I installed Mojave via Apple Configurator but that didn't work as it break during the revival of the last step because of the constant USB de-plugging from host/guest machine during the process. I think just the revival step in 2.12 should also work as it flashes also the bridge os and power it up which should avoid any data loss but don't take this for granted.
Initially, I tried to restore the system via Virtualbox where I installed Mojave via Apple Configurator but that didn't work as it break during the revival of the last step because of the constant USB de-plugging from host/guest machine during the process. I think just the revival step in 2.12 should also work as it flashes also the bridge os and power it up which should avoid any data loss but don't take this for granted.