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.
Dell OptiPlex 3060 MICRO DESKTOP PC COMPUTER I5 8TH GEN UP TO 32GB UP TO 2TB M.2
$350.00
HP Workstation Z640 2x Xeon E5-2623V4 32GB Ram Dual 256GB SSD K420 Linux GA
$161.24
Dell 14" TOUCHSCREN Laptop 8th Gen Core i5 16GB RAM 512GB SSD/256 Bluetooth W11
$235.00
Lenovo IdeaCentre 3 07IRB8 Desktop Intel Core i5-13400 16GB 512GB SSD W11H
$349.99
Intel Xeon E5-2667 V2 LGA 2011 3.3GHz 8 Core 130W 25MB 8GT/s CPU Processor
$14.99
AMD Ryzen 7 7800X3D 8-Core - 16-Thread 4.2 GHz (5.0 GHz Max Boost) Socket A...
$304.95
Lenovo ThinkBook 15 Gen 4 Notebook 15.6" FHD Intel Core i7-1255U 8GB RAM
$544.99
Intel Xeon E5-2667 V4 SR2P5 (3.2GHZ/8-CORE/25MB/135W) PROCESSOR CPU
$28.99
Dell Precision 3630 Tower i7-8700K 3.7GHz 64GB RAM 512GB SSD W11P- RTX 4000 GPU
$595.99
Dell 15.6" NVIDIA Gaming Laptop - Intel Quad Core i7 64GB RAM 2TB SSD Windows 11
$523.00