God bless you are not on macOS side.

Input

keyd

So for input remapping on kernel lever you can use keyd daemon. Amazing and simple thing. Example /etc/keyd/default.conf file:

[ids]
*

[main]

capslock = esc
esc = capslock

To emulate ANSI keyboard on ISO you can use this config:

[ids]
*

[main]
\ = enter
enter = \
102nd = leftshift

102nd is the right part of left shift that has been split. To get key code for your keys use keyd monitor command.

To use FN keys over media keys on lofree flow lite 100 execute

echo "options hid_apple fnmode=2" | sudo tee /etc/modprobe.d/20_lofree_fn_mode_fix.conf

and reboot.