Are there downsides that I'm not seeing to using SDA to invest offshore?

I've transferred some funds to USD using Shyft with the good exchange rate and plan to buy some ETFs on Shyft and on Interactive brokers.

My question is, will this make my taxes more complicated, is it even worth doing because of this?

I've read about W8BEN forms, dividends withholding tax etc, and it's all quite confusing.

I've done it mostly for the fees and the better brokerages and ETFs I can invest in directly, and I suppose better liquidity if I need to sell. But honestly I'm so new to this any advice would be appreciated, I also did it to diversify and not have everything with my bank and other South African institutions.