Personally, I’d probably go for Boner, just for it’s off-camber corners/roots/greasiness and steep sections that on a hardtail generally leads to me being more of a passenger than a rider!
But it all depends on what you class as hard.
Feed the Pony could be hard work if you don’t like rollers.
No Social is steep, but flows well.
Jawbone has the rocky section that steepens up a bit.
Splash and Dash has the steep entrance, and can be greasy as you get down the first section before you cross the stream, but after that it’s relatively easy.
3G/Repeat Offender are a bit steep and rocky.
Lone Wolf is a mud fest until it mellows out then it can a bit of a rooty nightmare.
New track has the drop, and a couple steep sections.