Do you need to be on 9.2 for it to downgrade you to 2.1.0? I know to enter hbl you'll need to be on a firmware that'll support booting to hbl. So take for instances you are on firmware 10.7 and have an entry point access to homebrew launcher, can just go straight to Decrypt9 and downgrade to 2.1.0 with 2.1.0 ctrtransfer? When you use 2.1.0 ctrtransfer you'll create an sysnand backup too and after that you can restore that after you get a9lh on your 2.1.0 3DS. So I believe that would work fine? The team has really made getting a9lh more convenient. Now you don't even need to make an emunand first in order to downgrade to 2.1.0.