I ran the automatic installer with my Google Pixel 4a attached.
The installer claimed I needed an OEM unlock code, but redirected me to Motorola’s web site.
That can’t be right, can it?
Also, is it really not necessary to install any custom recovery before installing iode, either automatically or manually?
I had the same thing with my 4a, I ensured OEM Unlocking is indeed enabled. The installer offers to skip this check, which is what I did and it went fine. No need to do install anything manually.
It seems like the installer wrongly identified your device as a Motorola, I have not seen this before. Was your device bootloader unlocked before starting the installer? fastboot flashing unlock should do it.
On the first attempt the OEM unlocking step couldn’t be skipped; the Next button wasn’t enabled.
On second attempt a day later it all worked fine. OEM unlocking was fine, and everything was installed correctly.
I noticed that the Bootloader remains unlocked, though apparently this device supports relocking it. Is that something I could or should do manually at this point, or is it best to leave it unlocked?
I successfully relocked the bootloader, but all user data was wiped. Is that to be expected?
Yes that’s what happens when you (un)lock.
Okay, that I should have known. Interestingly, on second restoration, much more of my device settings were restored (e.g., complete launcher configuration).
FYI: You should be prompted during install to relock or not, and yes, I am just reconfirming that either locking or unlocking will cause a reset of your userdata partition so all data is wiped as @perzarys notes.