I flatted each panel first with 1000 grit wet then 3000 wet, its very rare that I dry flat, even when I use a DA with Trizact discs I constantly wash the surface and sander to cut down any sand buildup under the pad as this buildup will create pigtails that require even more flatting to remove, I am lucky that I do not give myself any time restraints during my big details, so I can spend more time concentrating on not creating more work than necessary, of course it does not always go to plan but I do my utmost not to create more flatting as I will need as much paint/clearcote left on the panels so that there is enough left for the multi stage polishing.
There is a video on my channel showing what can go wrong and how I deal with it.