UPDATING revision and seperate edge-case question(s)

Having unexpectedly built world and kernel GENERIC on 3-8 Current, that is not
the principal system [1] ... browsing its UPDATING at the bottom the method(s) are
not so precise and/or informative [follows...]

[make world]
make kernel
installworld
.... where is installkernel
 
make buildworld
make kernel
mm...
make installworld
mm...
.... where is installkernel

but in motd where I save howtos

backups
check nosuid gone
make buildworld
make buildkernel
single user
mm...  [take good notes]
installworld

... and for a lack of time, have to put it all on paper (several draft revisions
within motd )

and in another /usr/src-old

svn sources
move make.conf
check nosuid
buildworld
buildkernel [ compare GENERICS assumed], add compatN etc
installkernel
mergemaster first type, using /usr/src/.../mergemaster.sh
single-user (yet)
installworld
mergemaster (complete )
install newly needed compatNif necc.
make delete-old  ( and sometimes a pipe y | make... or something)
restore nosuid
restore make.conf
rebuild nvidia-driver etc if necc.

AND steps I often take that I've not listed...

So, the latter example is more complete than the ones before it
However, I think other things may be missing
what if it should include a 2a.... make distribution  2b... make release etc which I have no 
  experience with...

/ end of requested another section in UPDATING with commented more-complete steps from
someone with more knowledge than I...
.............................
[1]

Edge case...
buildworld/kernel on another machine that is/was backup except that it ran out of space
on a few filesystems, so is NOT backup...
wishing for a foolproof method to script its expected installkernel/installworld onto an
attached main-os disk,  something with rsync... to expedite recovery from the main-os
disk installworld that fails at some point midway, meaning directory-by-directory fixes
using cp, gcp, rsync until the hosed installworld is usable again (I've done it before, that
is why I am asking for a feature that will preclude the installworld failure, something like
/work/ /stage/ in ports, where the /stage-installworld/ has been tested every which way
so that if the stage-installworld completes, the regular installworld is guaranteed to 
complete.  
Seeming about a half-years work on someone's part, just adding this edge case in
case someone has perchance crafted something similar, would jumpstart something
similar as a feature, and/or explain an equivalent methodology, to increase the
reliability of updating a system, say upon a critical security advisory happening to
every os on the web all at once...

...................................
ASKING NO RESPONSE to this email to here, do not wish to waste anyone's time, just
to put forth a few ideas...
..........................
Thanks for reading.

J. Bouquet