I was surprised to find out that along older VGA/HD LCD controllers now there are also 3rd party boards to drive 5K Apple screens. Look for "5k screen controlle

I was surprised to find out that along older VGA/HD LCD controllers now there are also 3rd party boards to drive 5K Apple screens. Look for "5k screen controller" on Aliexpress. Price range from ~130€ to 300+€, no idea about the quality.