Cannot Change HTML Variable Name From POST

I am trying to set up 2 separate CPT forms. One is relatively standard, the other I want to simplify by hiding the required set of fields, the listing only requires name, email and city.

I know this can be done through CSS and have hidden several fields. The issue, they are being hidden on all CPT forms, not just the simplified form.

I have attempted to change the HTML Variable Name from post. I cannot edit this field.

I have attempted to assign CSS class to the buttons but these are not appearing in the rendered code.

Should I be able to change the HTML Variable Name for the CPT fields to get a custom variable to use in a CSS declaration w/o hiding the fields on other forms?

Thank you.