Hi, here from Australia!
Here is some test results. When I first visited your website, I saw the currency was in USD. After 1s, the webpage refreshed itself, and showed currency using the local AUD currency here. The second time when I visited your website, the currency was in AUD right away.
There is an issue for first time visitors. For example, I have read towards the button of webpage, but then the webpage refreshed after about 1s, and the webpage went all the way back to the top(I was worried it could be a fake site. Especially as a fundraising website, the initially feeling of trustworthy is essentially)...1s refreshing time is too long.
You could potentially check Geo Redirect tool. It can detect your visitors locations and redirect your visitors instantly, appropriately 60 to 300 milliseconds, providing custoemrs seamless experience. The tool is easy to use and integrate within a few steps. No code is necessary. Shopify platform is perfectly supported.
You can test yourself how the website looks like from different countries. Here is a free tool: https://geotargetly.com/geo-browse. Just type in the website URL, and your testing countries, you could browse your website looks. It supports over 80 countires.
Hope it helps!