Saving iOS 12.4 SHSH2 using DFU apnonce collision at A7 (DFU defect)
macOS 10.13 (or later)

HOW TO SAVE SHSH2
Run the following script with the device connected in DFU mode.

./get.sh [device] [boardconfig]

Example
./get.sh iPhone6,1 n51ap

HOW TO RESTORE DEVICE
Run the following script with the device connected in DFU mode.
./recovery [device] [boardconfig]

If the device screen displays purple, you are successful.
If it does not turn purple, try again from DFU mode. You should succeed after a few attempts.

Finally, Futurerestore
fun :)

Credit
tihmstar: tsschecker, partialZipBrowser, igetnonce, img4tool
libimobiledevice: irecovery
s0uthwest: tsschecker, igetnonce, irecovery