I will be putting a modified VP on the inside of a six foot iin diam. dome with a 21 inch pitch. Never did vp in a dome before. What tools do you suggest so that it lays flat and can be burnished? I am thinking that I'll be sweating with the japan scrapers making tiny little layers. Help with any experience?

Get creative, domes aren't easy. Wish I could tell you an easy solution; I would just grab anything that you can think of that has any flex and stick it in your toolbox and figure out what works best for you. I have used a multitude of nonsense to accomplish a job. keep lots of towels on hand to help with the burnish.

go to an automotive supply store and pick up some flexible yellow bondo,.....what are they called, maybe a bondo spreader. I pick em up at my local hardware store. I get a handful of them for about 3.00.
Your burnish (that is if the trowel doesn't hit it parallel, will have to be polished with cloth.