How can we improve WHMCS?

Hello, it is possible to add option on product price page, like "Do not auto update currency exchange", for example i add price in USD, and add price in USD and in local country, because of the peculiarity of taxation, I would not like it to change constantly, I need it to be fixed, the one that I will indicate in local currency.
I understand that I can completely disable auto-update, but since I offer services in different countries, I need this function not for all products, but only for some.