I don't know why Sanding in multiple steps grits persists for new guys?
Sanding in multiple steps doesn't make the Clear shine any more than sanding one single step. In fact I believe it causes more work for the inexperienced.
I consider Sanding in multi steps very advanced sanding and polishing, You should try practicing on a piece of Lexan or Plexiglass first! Scratch it then Sand the scratch out bring it back to Clear with no sanding scratch! or try some other clear Plastic, you will quickly learn sanding in multiple steps is very advanced stuff.
I Polish Aircraft windows often after being scratched by Bird strikes or Jet Bridges scuffing Cockpit windows getting the scratches out and making the Glass clear again its not a job for the inexperienced, Its a lot of work to do it right.
Removing the previous sanding step sanding scratch is a lot more work and harder than most realize even those that think they are doing it right should try it on some plastic Plexiglass Acrylic or Lexan Plastic.
Your clear coat is Very thin even with 3-4 coats Sanding removes a lot of material quickly.
I strongly suggest sanding ONCE with 1200 and letting your compounds and Pads refine one single Sanding scratch with a ORBITAL variable speed buffer. Start with a Twisted Wool pad then after ALL sanding scratch is removed work with finer Pads and finer polishes.
Start with a compound designed to remove 1200 grit sand scratch then move on to a softer pads and a finer polishes. This is a good example of when Less is more or better.
Orbital polisher adapter for your Variable speed buffer.https://www.autobodytoolmart.com/dynabr ... 11979.aspx