Apply Calculated Value property based on other field value

I have a scenario where when I choose a dropdown value the Name field should be calculated value, something like

Dropdown value = 1 then Name=dynamic value based on other field values

Dropdown value = other than 1 then Name should be manually editable

But when you make a field as calculated value with formula, it will become read only and non-editable. How to overcome this.

My formula

ifElse(equal($opportunity_source_c,"monthlyreport"),concat(related($accounts,"name"),"|",$monthly_report_yr_c,"|",$monthly_report_month_c), "else make it editable")