While snooping around the stock init script, I spotted a variable, home, in the mountdata function standing out from the crowd. After doing some quick tests, the preliminary results are summarised as follows,
Prerequisite: The persistent overlay (.img, .aes or .inf) being on the same partition as the KNOPPIX file.
Functionality: Loading a specific persistent overlay at the boot time.
Usage: knoppix home=/mnt-system/foobar/dummy
*The dirname and basename cannot contain any whitespace characters.
*The basename needs to be unique if there are more than one overlay files in the same folder because the suffix cannot be part of the argument.
SGIN 15.6" Laptop Notebook Intel Celeron Quad-Core 2.8 GHZ 8GB RAM 256GB SSD HD
$171.99
Team T-FORCE VULCAN Z 16GB (2 x 8GB) 288-Pin PC RAM DDR4 3200 (PC4 25600) XMP
$35.99
A-Tech 8GB DDR3 1600 PC3-12800 Laptop SODIMM 204-Pin Memory RAM PC3L DDR3L 1x 8G
$13.99
Crucial 16GB (2x 8GB) Kit DDR3L 1600MHz PC3-12800 UDIMM Desktop 240-Pin CL11 RAM
$21.33
1x - T Force Delta RGB 8GB DDR4 Ram 3200
$18.00
HyperX FURY DDR3 8GB 16GB 32GB 1600 MHz PC3-12800 Desktop RAM Memory DIMM 240pin
$12.90
CORSAIR Vengeance RGB Pro 32GB (2 x 16GB) 288-Pin PC RAM DDR4 3600 (PC4 28800)
$79.95
HyperX FURY RAM DDR4 16GB 8GB 32GB 4GB 3200 2666 2400 2133 Desktop Memory DIMM
$14.85
A-Tech 256GB 4x 64GB 4Rx4 PC4-19200 ECC Load Reduced LRDIMM Server Memory RAM
$287.96
HyperX FURY DDR4 16GB 32GB 64GB 2666MHz PC4-21300 Desktop RAM Memory DIMM 288Pin
$119.80