best practices for updating?

Hi

I'm new to pkgbase and am running into problems with pkg upgrade of
the base packages. I should note that this is my first update of base.

I installed the system from a -CURRENT snapshot USB image and boot
strapped it using the HOWTO [1] from alpha.pkgbase.live
This process went smoothly, and the system has been running well.
Yesterday I tried to upgrade, but both attempts resulted in a
non-operational system. The first attempt did a naive pkg upgrade -r
FreeBSD-base. There were error messages indicating mismatched
libraries and other odd things. My guess was doing the upgrade in one
step failed because of an ABI mismatch between user space applications
and the kernel.

So I rolled back to the previous boot environment upgraded the kernel
package, rebooted, and upgraded the remaining components. The kernel
upgrade seemed to work, but upgrading the user space components
resulted in a non-booting system with errors from /etc/rc about
missing /sbin/sysctl and kenv (which appears to be true).

My question is, what step(s) did I miss when doing the upgrade?

[1] https://alpha.pkgbase.live/howto/bootstrap.html

--chuck