Prevent Fatal Error if plugin is deactivated

Absolutely love this plugin so hoping someone smarter than me can help.

I am looking for a solution to the problem that occurs if a client deactivate the plugin either by themselves or failed update process etc.

I would love to get this https://www.billerickson.net/advanced-custom-fields-frontend-dependency/ to work with CFS but cannot get it to work. I guess the API of CFS is different then ACF. I want to stick with CFS because it is lightweight and works better with FacetWP than ACF. Above example is a dream but if that is impossible then perhaps a solution below is doable?

I thought that perhaps another way to avoid fatal error is using a

if( function_exists('CFS()->get') ) {

}

but that does not seem to work. Nothing shows up frontend. I am just guessing the function name based on a video on Lynda where there are a similar example for ACF.
I know the if function_exist would remove the custom fields content frontend but at least the fatal error will be gone and visitors can see all other content like post and pages.

Thank you in advance

https://www.ads-software.com/plugins/custom-field-suite/