2sc5200 1943 can be biased more in class A a/c SOA

I have seen the datasheet of 2sc5200 for which
at lower voltages like 30V the collector currents are rated pretty high as high as 4Amps

in that case after observing the hiraga super class A 30W project its said that Hiraga is biased at 1.75Amps so in that case i have observed the SOA of the transistor and found that so why cant 2Amps of bias current be used? can that be?