In this engine there is literally NO reason on ANYTHING.
With regards to floating point precision, the engine has trouble past 2km no at 640m.
And even then, it’s pointless to argue that “it’s built and maketed for large words” or whatever - a large world will always require world origin shifting. The engine does include the function.
It’s also fairly easy to set up for “infinite” geometry without ever incurring into floating point issues in practice.
I doubt you’ll ever get an answer as to why - but here’s hoping.