change currency - not showing in checkout

In our shop, we're offering quite a few different payment options to cater for both international and local visitors, but we need the options to change depending on the currency, as the local options can't handle foreign currencies.

I'm noticing that the "Currency" sidebox seems to disappear whenever you are in the checkout section, even though we would like to advise our customers that changing currency will allow them to use different payment options.

Is the box meant to disappear, and why does it happen? Would it be a good idea to override that behaviour, or does it serve a purpose?

The currency sidebox is automatically disabled during checkout so that people don't change it mid-stream, either by mistake or on purpose. This prevents confusion from the totals changing and in some cases needing to be recalculated all over again.

I wouldn't recommend changing that without doing some extensive testing to be sure you're certain that there are no adverse effects related to the change ... and certainly not on a live site until you've vetted it on a test site first.