iPhone 11 Battery Health

Until the battery drops below 80%, it's fine. There's no reason to be checking battery health unless your phone isn't working properly or your warranty is about to end. So, in a month or so, check it again, if it's at or below 80%, make arrangements to have it replaced under warranty. If it's above 80%, you can safely ignore it for another six months.

No, there's nothing to be alarmed about. Battery health starts declining the moment the battery comes off the assembly line. It continues to drop until the battery is no longer useful. There's really nothing you can do to prevent that.

Used Optimized battery charging and stop worrying about it.

Apple would replace the battery under warranty IF and only IF, Battery Health dipped to 80% or less in the first 12 months of ownership. Since you have now owned your phone 10 months, it is highly unlikely you will have a valid warranty claim two months from now.

You're welcome.