Linde makes trucks at load centers longer than 24" starting at 17,500# capacity and up. Most manufacturers rate their trucks at 36" of 48" load center starting at about a 40,000# capacity.
I'm not sure why others don't increase their load center below that because I can't imagine a load that weighs 25,000# that is only 4' long for example.

you can see the "Standards" for forklifts sold in the USA, at itsdf dot org, as long as you agree to not try and sell copies of what you download for free.
ITSDF is/should be the bible of forklifts, and are now the "keeper" of the B56.1 standard, which they took responsibility for, from the ASME, as it is the "Industrial Truck Standards Development Foundation".
Before ITSDF, ASME wanted to charge you something close to a private US college education for the ability to -look- at the standards, and it was always a great mystery as to what standards really were, for most people.