Hi!
It's a common problem, not a lot of people get this right. When I boot with lang=ru cheatcode, /etc/init.d/knoppix-autoconfig automatically selects xkeyboard=ru, too. The problem is that to get any work done I still need to go to keyboard layout settings, add 'us' keyboard and select some switchng hotkey (it's impossible to type commands or URIs with 'ru' layout, you'll get ыуечлиьфз -щзешщт пкзЖсекд_ыршае_ещппду гыбкг and реезЖ..лтщззшчютуе. instead). It's not a grave problem in Knoppix (not only I can add xkeyboard=us to boot parameters, there is even a GUI to setup layouts), but it can be solved completely in different ways:
1) Add another cheatcode which would set XKBOPTIONS in /etc/default/keyboard, so it would be possible to boot like this: knoppix lang=ru xkeyboard=us,ru xkbopts=grp:ctrl_shift_toggle
2) Copy the logic from, for example, d-i (https://sources.debian.net/src/conso...n.config/#L487): they first set the layout[s] based on the locale, adding 'us' if needed, then add -option grp:alt_shift_toggle,grp_led:scroll if there is more than one layout (also, lv3:ralt_switch if the layout is single, but non-US).
Best regards,
Ivan
DELL PowerEdge R730XD Server 2x E5-2680v3 2.5GHz =24 Cores 32GB H730 4xRJ45
$271.00
Dell PowerEdge R620 Server 2x E5-2660 v2 2.2GHz 20 Cores 256GB RAM 1x 480GB SSD
$139.99
Dell PowerEdge R730XD 28 Core Server 2X Xeon E5-2680 V4 H730 128GB RAM No HDD
$389.99
R630 DELL 8 x 2.5'' POWEREDGE 2X E5-2680V4 32GB RAM IDRAC ENT & NDC 2X 495W PSU
$169.95
Dell PowerEdge R720xd 26HDD 300gb 2.5-inch E5-2697 X 2CPU 384RAM 7.2 Tb HDD 
$180.00
Dell PowerEdge R630 Server 2x E5-2640v3 2.60Ghz 16-Core 64GB H330
$182.65
Dell PowerEdge R620 Server - 256GB RAM, 2x8cCPU, 120Gb SSD/3x900Gb SAS, Proxmox
$320.00
Dell PowerEdge R640 Intel Xeon Silver 4114 2.20GHz (x2) 128GB RAM No HDD H740P
$649.99
DELL PowerEdge R630 8SFF Server 2x E5-2650v4 2.2GHz =24 Cores 32GB H730 4xRJ45
$240.00
Dell PowerEdge R430 3.5 1U 2x E5-2690 v3 2.6ghz 24-Cores 256gb 4x Trays 2x 550w
$359.99