Using TV remote to control Kodi on Pi5

What about adding a FLIRC to you RPi?

I use it with my Harmony remote and zero lags scrolling or button commands.

Pricewise the OSMCremote and a FLIRC is about the same, OSMC RF remote works out of the box.

The linked thread is correct because the TV is the receiver of the IR signals and sends a button code (the duration info seems not parsed or reliable) to the RPi5 via CEC.

Technically possible, but I don't expect this behavior on a TV:
If the TV interprets the buttons based on how long they were held down, it may be sending a different CEC button code.

The important part regarding the breaking change seems the Android/Google TV generation. Previous generations of SONY TVs are able to passthrough the tuning and menu keys to CEC, if you configure this in the Bravia Sync settings for external inputs.
After switching to a newer TV of the same brand, I'm facing for the issue, that the menu keys and some other keys aren't passthrough anymore. Before it was possible to use the channel-up/down keys to navigate page wise through long listings. Now it's possible to open an additional menu for HDMI via info key and send a CEC command in behalf of the TV, but this key was also usable before directly.

My workaround is currently to move one step to right in the movie list to focus the scroll bar and move then with the cursor keys to jump to the next page(s) faster.

If this, that you meant with slow scrolling, perhaps you should map one of the color keys to the channel-up/down function. If not, you can only try to play a little bit with the CEC settings at System -> Input -> Peripherals.

To check which keys are going passthrough via CEC with your TV, you can stop KODI and use the cec-client command.

• Stop KODI
  systemctl stop kodi
• Start the CEC-client
  cec-client

• Press the keys on your remote control step by step and write down a list of all available keys. Here an example for cursor right:

  Code

  DEBUG:   [          189968]     SetCurrentButton right (4) D:0ms cur:17f
  DEBUG:   [          189968]     key pressed: right (4) current(ff) duration(0)

• Stop the cec-client process with CTRL-C
• Start KODI again
  systemctl start kodi

With that information you can make then the changes like you want to the keymap file.

EDIT:
I played a little bit with the settings (System -> Input -> Peripherals -> CEC Adapter) and could clarify 2 things:

• Set „Remote button press repeat rate (ms)“ to 100ms fixes the „slow“ repeat rate compared to a IR remote control.
  Reducing "Remote button press delay before repeating (ms)" to 200 makes it even faster to switch in repeat mode (scrolling), but could be make some trouble if there is "longpress" support in the future.
• It‘s important to switch the TV to the HDMI sub input/device -> "Kodi HDMI 1 Player" not only "HDMI 1" to get the tuning and number keys to work.

By the way, the period key on the left of the number pad is assigned to the context menu by default.