IVV vs VOO for future expat?

Hi, I hope to get some advice from experienced investors. I started investing in IVV S&P 500 mid last year. I chose IVV because of the simplicity of it being on the Australian stock market for Australian tax reasons.

But my partner and I recently started considering retiring in South East Asia within the next 10 to 15 years. I may not start cashing out portions of the investment until just under 20 years in the future. My questions are: Should I continue to invest in IVV for the next 15 years then sell (before I move or after I move) and buy VOO or other US-based ETF) then continue to invest until I need to take percentage or all of it out? Should I sell it now and start investing in VOO before I will lose a large percentage of my returns to Australia's CGT? Is the currency conversion rate and the weakening Australian dollars going to make one strategy or the other better?

Thank you!