Should I add more funds to my Syfe REITs+ or open a core defensive or balanced portfolio?

If I were in your position, I would open another portfolio to complement your REIT+ portfolio. Key reasons being:

1. REIT+ is concentrated in, well, REITs. While diversified between REITs, this does subject your entire portfolio to REIT specific risks, e.g., changing of gearing ratio limit, i/r changes etc.

2. REIT+ is concentrated in Singapore REITs (yea, I know they own overseas property, but still). This creates a huge concentration risk, considering Singapore may not always be a bustling hub for business.

Between Core Defensive and Core Balanced, both are great portfolios, but the choice should ultimately lie in your own risk appetite. If you can stomach bigger swings, Core Balanced or even Core Growth, will give you (likely) higher returns but more volatility. If you're more risk-averse, you can choose the Core Balanced or Defensive portfolios instead with more focus on Fixed Income and Gold.