we have developed shopify currency converter app that have feature of selling in multi currency its work awesome on theme but on checkout page its work perfect on information page / shipping page / payment page but when user pay the bill final page thank your ( order page ) it show store default currency.
i have test on development store it work perfect but on subscription shopify store it won't work.( on thank you page )
Video link ==>> https://youtu.be/IlRtLzZRJa4
checkout in multi-currency will only work on Shopify Payments method. So if you use paypal, COD or other method it will converted in default currency.