Allow to add parameters?

[SilentStorm]

I was trying some fancy blueprinting with formulas, and maybe I just don't really understand how they are supposed to work / be used yet. However it appears as to be able to use formulas you have to have a unique number somewhere that you can give a variable name.
Then you have to have another unique number to use a formula for.
However it appears it's not possible to add these in the parameters window, without having some number in some sort of combinator that then will get picked up by the parameters window.

Sadly once you delete the source of the parameter from the blueprint the parameters are gone as well.

Maybe I simply haven't found a use case for them yet, but it seems like it's very limited and I cannot foresee a use for these with these limitations.

[Koub]

So ... what's the suggestion ?