Any advice or thoughts on my portfolio?

My opinion:
1. Overweighting US. IWDA is already 65% US. Add QQQ in and you're overweighting FAANG and the "usual suspects".
2. Too little exposure to China. I am of the opinion China will overtake US. It's just a matter of time.
3. Local bias. Singapore is only 0.4% of the world economy.

With this portfolio, you are (if my calculations are correct):
~53% US
~5% China
~11% SG
~31% RoW (rest of world)

My suggestion:
Instead of IWDA+VWO, go with VWRA. This one ETF alone covers both developed and emerging markets.
Instead of QQQ, invest in a China tech ETF. 9169.HK and KWEB come to mind. There are a few more good ones, just Google :)
Use the funds originally intended for VWO for the China ETF instead.
Reduce Singapore exposure.

I personally am:
35% US
45% China
15% RoW
5% SG

Sounds pretty logical to me. If i were you, I'll be allocating more towards QQQ and ride on the growth that big tech firms are enjoying right now. With the trend of AI/IOT/5G/Cloud Computing coming up, tech is really where the growth will be in my opinion but that is still up to you to decide how you want to allocate.