I tried to sideload cyanogenmod 14 onto it, and the tool for unifying the partitions crashed and broke the partition setup on the phone.
This left the phone in a non-bootable state.
I tried reflashing the bootloader with s1 tool and testpoint, but it fails with HDR Block not accepted - this is where I found out about the trim area being a thing.
So I think that since nothing has been written to the flash, only the partition table was erased, that the trim area is still there.