LOLIt makes no sense economic wise.
Singapore and Malaysia haven’t much people. The demand would be minimal.
It’s better to wait on Vietnam Hsr. We have 100 million people. Different scenario.
Vietnam plan on low speed railway for 30 years, not finalized yet.
Vietnam principal route is the 1,600 km (990 mi) single-track North–South Railway line, running between Hanoi and Ho Chi Minh City. This was built at the metre gauge in the 1880s during the French colonial rule.