Hello senzalice,
Except that I get NO response when issuing ir-keytable -t
It sounds that you don't use the right dtb.img file. Inside the external installation media (usb-stick or sd-card) is a folder called device_trees. You have to copy the file xxx.dtb (the one that fits your hardware) to the root of the instllation media. Then rename the file to dtb.img. After a reboot, the system should recognize your hardware and your ir-receiver should work.
If you do a ir-keytable -t in a terminal or over ssh, every stroke is promted with the ir-code on the screen.
In my case i took an existing rc_maps.cfg and modified just 6 values.
Before you start lirc and Kodi again, don't forget to activate the config with
ir-keytable -a /storage/.config/rc_maps.cfg -s rc0
I have needed 3 attempts untill it worked like it should Keep on trying.
Regards
TMM