In the Internet there are some dealers who advertise that they can supply the Suzuki OEM tool, part no. 09940-30250. See for example partzilla.com
https://www.partzilla.com/product/suzuki/09940-30250Unfortunately there are no good enough pictures of the tool.
Anyway, I managed to uninstall one cartridge without the holding tool and noticed that there are four little holes in the head, 17,5 mm apart, 25 mm diagonally. I made a tubular tool with four pins matching the holes and by using this tool I managed to uninstall the other cartridge.
I assume that the Suzuki tool might be similar to the one I made and that's why it is suitable for all 14's.