Usage of comma before ‘but’ in a long / complex sentence

I’m subtitling a spoken word piece, and the phrase, which is an answer to a question, is

• Identifying and accepting something not in its true form but as something else.

I think there should be a comma before ‘but’:

• Identifying and accepting something not in its true form, but as something else.

The strict rule of grammar would be that a comma is only permitted before an independent clause, which “as something else” obviously is not. But the phrase “Identifying and accepting something not in its true form” is one concept and already quite complex. “but as something else” is a qualifying statement and a counterpoint to the first phrase. So when you see the text without any punctuation, the mind has to work that out through reading it through to the end and then work out that that’s what it means. If you have the comma, that gives you a shorthand to tell you that there are two different phrases which counter each other. So you can immediately approach it like that. It speeds up your comprehension which is important in a subtitle, and meets the purpose a comma to separate concepts into logical segments so the sentence can be readily understood.

What do we think – should the sentence have a comma or not? Thanks.