I wouldn't give up what you have. I fear you would be risking too much. None of us knows the ultimate likelihood of a waitlist clearing. But given this would be for Suites on LHR-SIN, I think the odds are quite slim.
While KF Gold puts you higher in the pecking order, I don't think it will matter much.
As a Solitaire, I checked availability in March 2024 and was able to find immediate Suites redemption availability (A380 both sectors) on around +/- half the days in March. Some days with short connections, some days with long, some days with two options. I don't know how many, if any, are currently available to KF Gold? The question is at what point, if ever, will SQ make that redemption availability open to those waitlisted?