To be honest, I had already read the cheatcodes before and I'm largely familiar with most of them, as I had previously installed Slax.
I found this section, which is presumably what fanthom was referring to:
... Loads Porteus from the specified device, folder or ISO file.
'from=/dev/sdb2' will attempt to load the Porteus data from
the second partition on your second drive.
'from=/mnt/sda2/linux-testing' will attempt to load Porteus data
from the 'linux-testing' folder placed on the second partition.
'from=/linux-ISO/porteus.iso' will attempt to load the Porteus
data from an ISO file placed inside the 'linux-ISO' folder.
If the destination partition is not provided with this
cheatcode, the booting script will search through all available
devices for your data.
Also this, in the introduction of the cheatcodes section:
Here's an example of what the boot line would look like, adding the noauto and copy2ram cheatcodes to a standard Porteus boot option (which already has some other cheatcodes by default):
APPEND initrd=initrd.xz lxde changes=/porteus/ noauto copy2ram
These cheatcodes can also be added to the APPEND line of your /boot/syslinux/porteus.cfg entries (or other bootloader config files) to apply them automatically on every boot
Placing "APPEND from=/dev/sda2/porteus/porteus" in /etc/lilo.conf
generates an error when I run /sbin/lilo -v
Placing "APPEND initrd=initrd.xz changes=/porteus from=/dev/sda2/porteus/porteus" in /boot/syslinux/porteus.cfg
has no effect and I get the error on booting as before.
However, in view of the nature of the responses I have recieved on here, I'm very much disinclined to pursue this any further.