You're welcome. Btw, he wasn't the Naval Attache' but the Assistant Attache for Air. The Japanese Air Forces (Naval and Army) were his specialty, along with learning as much as possible about Japan's industries. Jurika actually helped with target selection and advised aircrew to make sure they didn't crash-land in Japan, as he expected anyone who did so to be executed.
If they take the NEI 2-3 weeks later, it doesn't affect the course of the war that much: They were in Borneo, Ambon/Timor, and the Celebes in Jan-Feb, so you're expecting either Sumatra or Java to hold out longer than they did. Once Singapore falls, Sumatra is only a matter of time. Java was the last one, so if Java holds out, the Japanese simply consolidate their previous gains, maybe bring additional land-based air assets in-theater, along with Kido Butai, and mass for the final assault. They were a month ahead of schedule-the Java invasion was originally set for April '42. It would give the Dutch time to attempt to destroy oil facilities-and they did accomplish some demolition, but most were still captured intact OTL. The Sumatran fields were seized intact, by Japanese Naval Landing Force paratroopers, so you might even see additional airborne landings to go along with the actual amphibious operation. It may, however, bring Kido Butai home early-they were on their way home OTL from the IO Raid when the Doolittle Raid went in, so they'd be recalled from SEA post-haste.....but there would be by that time, ample land-based Naval Air assets (21st, 22nd, and 23rd Air Flotillas) to handle things.
That is only one side of the war. Presumably the Allies aren't playing hopscotch so what are they doing with the three weeks? I doubt they would bring in the Kido Butai unless that was part of the plan all along. They are still a week ahead of schedule so why bring in a bunch of carriers? They gulp fuel like crazy and with them fighting wildcats and buffaloes instead of buffaloes and biplanes the Japanese Navy will probably lose more planes and want to replace them, particularly if they are still ahead of schedule.