To what extent is it applicable to not edit the first draft as one goes along? I started to write Act 1 of my book. I keep going between scenes as I get stuck and have to add to the barebones writing ifvmine that is 90% dialogue.
It’s about finding a creative process that works for you. Most of the time, you want to be moving forward, maintain the momentum, and complete the story before going back and reworking things. This also has a benefit of foreknowledge, so when you go back and start cleaning things up, you’ll have a better idea what things are building to. You can trim out details that were abandoned, and play up (or add) details that foreshadow where you’re going.
A lot of, “you must write this way,” advice comes from a good place, but may not be applicable for you, personally. Some writers, I used to be one of them, will start with nothing but dialog, then go back through and start fleshing out the scene. There’s still elements of that in my rough drafts. Lost of dialog, light on description. There’s nothing wrong with this, and no rule that your rough draft must take a specific form. If it’s useful to you as a stepping stone, your rough draft has done its job. If your rough draft becomes an impediment to your writing, it’s not doing its job.
The advice against editing your rough draft is for your benefit. It’s very easy to start redrafting pieces as you go along, get caught cleaning up one segment, and lose the bigger picture. By the same measure, you might work better writing the dialog and then immediately going back and writing the rest of the scene. If it works for you, it’s not wrong. If you find yourself writing scenes in random order, and later sort that out, clean it up, and turn it into a coherent story, you’re not wrong. If you write in segments, go back, redraft them until you’re done with them, and move forward creating a serialized story, you’re not wrong.
If your method works for you, it’s not a problem. No one cares how you got to your final draft if it’s good.
If your method does not work for you, trips you up, causes problems, distracts you, and prevents you from getting to your final draft, that’s a problem. That’s where advice like this can be very helpful.
Personally, from where I’m at today, I’d say, don’t go back unless you need to. There’s nothing wrong with a rough draft that reads like a script.
Sometimes you may need to go back and make notes for future revisions. If that’s the case, keep it short and simple, it’s problem for future-you to deal with. There’s wrong with simply inserting notes into your rough draft, and getting back to the content at hand.
Above all else, I strongly recommend not sacrificing what you’re working on at the moment to go back and build for it. You can do that at your leisure. But, I’m not you. If working on that foundation helps you put the later scenes together, then that’s the right choice for you, and the wrong choice for me.
Remember: you’re not being graded on your rough draft. It can be as messy as you’re willing to tolerate. Getting stuff down, being able to clean up and build on that foundation is critical. No one else has to see your drafts until you’re comfortable with them.