complete set

If you complete a series you get the double greeen v sign, that is great!, but if the series have a variant you don't get the double. Please let me have the double for a complete set without variants.

Do you mean the double green tick you get when you have 1 listed on each date line of a coin's page?

It would seem that you'd need to get all the variants to have a double tick on a page of a coin with variants, no?
Otherwise you'll have to learn to be content with a single green tick, like I did. Sorry.