My father was one of those on Okinawa, for the battle. He was an army engineer, in a battalion that specialized in building airfields. They were the first engineer battalion sent into the pacific after Pearl Harbor.
They stayed in Hawaii long enough to build all the WW2 army airfields, then went for the island campaigns. He never said how they felt about waiting for the invasion.
McArthur wanted the engineer regiment that my father’s battalion was in for the occupation of Japan, but they had been in the Pacific Theater longer than any other army engineer regiment. By regulation they should have been the first regiment sent home.
According to my father, the senior NCOs met with the general commanding Okinawa, and told him that if they weren’t sent home right away, the regiment would commandeer ships and sail away.
They were the first to board ship, and left behind brand new heavy equipment and machine shops that had been issued for invasion work. This is all according to my father.
Correction: My father’s battalion was the first to be sent to Hawaii after Pearl Harbor. The first sent into the Pacific went to Guam, with unfortunate consequences for them.
He was later stationed in Japan for 6 months and as far as I know never had any problems with the Japanese.