Hey... if I follow the install instructions of SARPi, I end up missing . Is this intended?

Not sure. Perhaps if you offer a little more detailed information I might be able to understand the context of what you're asking.

In any event, users should install and run the official Slackware versions on the Raspberry Pi computers, where possible.

I'm talking about these instructions from SARPi3_64.README inside sarpi3_64-installer-boot_slackcurrent_06Mar24_sp1.zip:

The kernel package from SlackWareAArch64-current, kernel_armv8-6.6.21-aarch64-1.txz, has the script, and the one I'm instructed to replace it with, kernel_sarpi3_64-6.6.20-armv8-1_slackcurrent_06Mar24_sp1.txz, does not. Neither did I find it in any other package provided by SARPi. On bootup there's a message printed that it's missing and there's a fallback in place.

I was under the impression I'd have to follow this Readme to get a working SlackwareAArch64 on my Raspberry Pi 3. Is that incorrect?

If you're expecting SARPi to work (or be) exactly the same as the official Slackware Linux operating system then I'd advise you to install the official Slackware Linux installer software and ignore SARPi.

SARPi exists as an alternative when there's no other options available. I believe the Raspberry Pi 3 and 4 are supported by official Slackware Linux software. I always advise people to use official Slackware software where possible, rather than SARPi, because then they don't run into issues like the one you have right now.

You're not incorrect, because SARPi makes it possible to install Slackware Linux on the Raspberry Pi 3. Although it appears that you may not fully recognise and understand that there are differences between the all-inclusive official Slackware Linux software and the lesser selective experience of what SARPi offers and exists for.

Thank you for your answer. While not helpful, it certainly is enlightening. And I agree it's mostly my expectations that are at fault here.