Welcome Yankee. Similar situation, different country. I agree 40 hours will feel like a cake walk after this...but I'll probably just punch out. By the time I'm done in 18-24 months, I'll have 24 years in...the last 10 of which have been 70+ hours each, and before that at least 60+...so that is at least equivalent to between 36-40 years of 40 hour weeks. As long as I have the FI right, then I guess I've earned my RE...
Good luck in Sing...and with your plans for FIRE.