How can we improve WHMCS?

As a hosting provider, our products have setup fees for certain config options.

So, if you have some configurable option that is charged only once (setup fee) and recurring price is free, client can order the product without this specific config options and later upgrade through the upgrade/downgrade config options function, the system will not charge setup.

We would like the ability to charge the setup fee when clients upgrade a configurable option.

As we see it there are a few potential solutions:
1. Configurable options with setup fees cant be up/downgraded. ( Mandatory to make this behavior active/inactive via checkbox ).
2. Add in product setup, another checkbox, next to "Check to allow Upgrading/Downgrading of configurable options" to charge setup yes or no.
3. Inside of the config option configuration. You have a checkbox "Hidden". Add a checkbox "apply Setup" ( bad name, as its missleading, but you get the point i guess ).
So the admin can decide if he wants for this or that config option to have the setup being charged on upgrade/downgrade yes or no.