Vinyl floor in basement bedroom advice

My finished basement has a bedroom that the carpet and pad has been removed from (sump pump installed after a leak) , the concrete floor is fairly smooth, but not precisely flat. I could have a leveling sealer put down, then vinyl planks installed over it…However, the flooring guy seems to think that 1/2” planks, including the built in underpaid, would lay flat. I hate to spend the extra $$ to have it sealed/leveled, but definitely would if going with a thinner product. Does it sound reasonable that a thicker product would have enough padding to absorb minor variations without leveling first?

(My husband died 4+ years ago, and I am clueless about house maintenance stuff, so need second opinions! Thanks).