I bought the HDMI to MIPI LS055R1SX03 5.5 inch 2k IPS LCD module 2560*1440 from Aliexpress, Plugged it, and used a configuration found on the internet to be able to see any image.
Surprisingly it worked perfect after putting the following configuration:
hdmi_force_hotplug=1 hdmi_timings=1440 0 50 10 35 2560 0 4 2 2 0 0 0 50 0 198000000 0 hdmi_group=2 hdmi_mode=87 hdmi_pixel_freq_limit=500000000 hvs_priority=0x32ff max_framebuffer_width=1440 max_framebuffer_height=2560 framebuffer_width=1440 framebuffer_height=2560 framebuffer_depth=24 framebuffer_ignore_alpha=1 config_hdmi_boost=4 gpu_mem=192
The problem is that everything is so small it's unreadable. I guess it's because the resolution is too high for such a small screen.
I figured out that if the above is working configuration, so somehow we can deduce a lower resolution configuration.
I tried to decrease the resolution, putting half of the size of the recommended working resolution: 1280 X 720 @ 25Hz but no image shown. obviously something is missing, or maybe there is another way for me to see something...