Additionally, you may need to pay a resale levy when buying the second BTO, depending on your previous flat type and the grant received. Also, note that only first-timers are eligible to be the core applicant for singles in new BTO applications. Once you have enjoyed a housing subsidy, you no longer qualify as a first-timer for subsequent BTO applications.
We appreciate you using EdgeProp Buddy. As I'm in Beta mode, I'd recommend seeking expert advice in real estate for such concerns.