Q: I need to enable the registration during checkout only. Currently I'm using Amasty One Step Checkout and magento 1.7.0.2 do you think it will work fine?
A: It may work since you need to enable the registration on the checkout and only log-in on the registration section. However, we are not 100% sure for this as our extension works best with the default magento theme and works with the other themes after placing the extension files from base theme to the current theme.