The LG should do for hatching only, but you need it like today to get it up and ready and watch the numbers. You'll have 30 days to return (check with the store to be sure) so if it doesn't function for hatching, you can take it back for a refund.
I've had staggered hatches before. Funny story. I was at a county park where they have a mini farm for the kids. Found a black hen in a really bad spot, nesting. She had it in a metal trough with 12 inch sides. No way were chicks going to be able to get out of it to eat and drink, and it was hot and dry out. So I picked up each egg, any that there too light I left there. Took the "heavy" ones home.
Already had eggs in the incubator, placed the "stolen" ones.
Next day, I have a chick. Ooops! Unless another of the new eggs hatched, this was going to be a problem. Nothing else from her nest hatched, and mine had another 17 days. So I had a little pullet glued to my every move. Finally another hatched, a little black rooster. Matching pair! She hated him. It took a good week for her to accept him (and herself) as a chicken. I don't know if she thought she was a duck, a dog, or a human. She hung out with all 3.
The biggest issue with staggered hatches, is humidity. Followed by hatched chicks knocking around the other eggs. If you have a way to separate the eggs due to contain the hatching, that would help. Humidity... you would have to not open the incubator at all during the hatch so that it didn't fluctuate lower than it already is for regular incubation.
That little black pullet hatched just fine in regular humidity. I didn't know she was coming (luckily I was hand turning then) until my evening turn. I saw the pip and left it shut, and didn't resume turning until she was out.
For eggs due to hatch, they can't be in a turner. So a staggered hatch with a turner won't work.
