Help on downgrade

I need to run a test to help a customer and want to downgrade the OS of a photon to 0.6.3

it is currently running 0.7.0

I compiled the app using --target 0.6.3

Then using the cli I pushed
particle flash app-0.6.3.bin (My understanding is you need to push an app built using only 0.6.3 features first)
particle flash system-part2-0.6.3-photon.bin
particle flash system-part1-0.6.3-photon.bin

After the dust settles the device is still 0.7.0

I don’t understand. I followed these instructions: https://community.particle.io/t/upgrading-and-downgrading-particle-device-os/43660

did something change?