I have 4 manuals that have data for the 6X45mm and none list Varget.
My guess is that while it will work with those bullet weights you may not be able to get enough in the case to see velocity achieved with more suitable powders. Again just an educated guess but you may not be able to put enough Varget in a case and seat a 70gr bullets to get close to a max.
I know the load of H4895/70gr Nosler I use in my Cooper 6X45mm is a heavy compressed load and it’s faster burning than Varget.
I load varget in my 6x45.usualy around 26.5 grains as that is all that will fit and still have room to start the bullet.I believe that you can dip the case in the powder and fill it up as I can't get enough powder in the case to show any pressure signs.I also use benchmark and realy like it.you can use load data for the 223 as a starting point