The split between conversion_rate and topup_conversion_rate is a smart call — it's exactly the kind of detail that looks minor until you're trying to run a prom

The split between conversion_rate and topup_conversion_rate is a smart call — it's exactly the kind of detail that looks minor until you're trying to run a promo without breaking your revenue reporting. Keeping invoices anchored to a single currency while letting the credit layer flex is the right abstraction.