@jakfishFWIW, when I did this on stock Android 2.1.2, I only did "fastboot oem off-mode-charge 1", and it worked fine with the battery animation present on the screen by default. YMMV, I guess.
I use a Windows PC for this kind of work, and download and install "Minimal adb and fastboot". Forgive me if the following "how to" is too basic, but it seemed you might want some foundational info. I just did all this a couple of days ago, so it's still top of mind.
Once Minimal adb and fastboot is up and running on the PC, it will open a terminal or "cmd" window in PC speak, and you can ente