We recently had a revocable trust set up in Virginia where we live and own property. It is my understanding that the trust is written specifically to comply with the laws of Virginia. The attorney said that even if we were to then move out of state, that if the trust were to be challenged after our passing, that the laws of Virginia would apply.
Given that, I think you would need to find out what the laws are in Singapore regarding trusts.
...you can check out any time you like, but you can never leave...