I am not 100% sure I understand what you mean when you say "unload 16 binaries", but the steps I do are:
1. I install a fresh ASE16 on a new machine.
2. I build a couple of temp databases to mimic the setup we have in production, I also make sure automatic upgrade is enabled.
3. I take a disk snapshot of my 15.7 databases from my production server.
4. I create new disk volumes based on the snapshot I just took.
5. I mount these volumes on my ASE16 machine.
6. I mount the 15.7 databases with help of a manifest file on my ASE16 machine.
7. I take the databases online, and they come online just fine, but do not get upgraded.
8. I run the upgrade manually, and still no upgrade.