WARNING: the stage1 binaries which can be used with 2.0 are mutually incompatible with the ones usable with 1.x. Using old stage1s with 2.0, or new stage1s with 1.x WILL LEAD TO AN UNRECOVERABLE BRICK. As of now, both delebile's and my own fork of A9LH have been updated for this. DON'T USE pre-made stage payload bins found randomly on the internet (Plailect's guide will be updated for this).
Changed the key2 used for the A9LH installation to the "perfect" one found by
@gemarcano. This produces a perfect branch to the first usable offset in firm0
Changed the FIRM0 to the 8.1 New3DS one. These two changes, combined, net a total of 1312 extra bytes usable with stage1
Changed the A9LH updater to update both FIRM0 and the key2 if the old key2 is detected. For this, you'll need the 8.1 New 3DS FIRM named as firm0.bin in the a9lh folder
Added uninstall feature. This allows you to quickly uninstall A9LH, on both Old and New 3DSes, but only if your sysNAND isn't 11.0 or greater to prevent you finding yourself with an unhackable console. Please note that if you uninstall A9LH, you'll need a system version of 9.2 or lower to reinstall it
Added the 2xrsa entrypoint to install A9LH directly from 2.1. This also dumps otp.bin to the a9lh folder for future usage. (thanks to
@dok3 for this!)