I’m not going to claim expert status.
But the most important part is having your bed layer of surround speakers accurately set...
to the best you are able. From there, placement of the Atmos speaker is a little more flexible. Keep in mind, Dolby has to define it, but we all have different rooms that we apply that definition in. So to the best of your ability, follow the recommendation for general placement.
One friend here has inspired my understanding. He likes his L/R surrounds a little behind, closer to that 110° placement than directly at your side. From there, you are able to get a little more separation when placing the Top Front or Top Middle Atmos speaker which is what you are doing. As yours is an angled elevation speaker, you want to mount it as high as necessary to have the angle of the baffle facing your LP as much as possible. You don’t need to go to the length of having it aimed directly at you, though if you wanted to buy special hardware, you could.
Regardless, for Top Front placement, you would put it about 3 linear feet in front of your LP. Top Middle I wanna say is better almost a little in front of you, but not as far as that top front location. Top Rear would be 3 feet behind.
If you think you might at some point add Top Rear, definitely go for Top Front placement. Either way, my understanding is that Top Front may be the better placement because it does give you better separation from your other surrounds.
Lastly, don’t fret if it’s not textbook perfect to the guidelines. As long as you do your best to match the “ideal location,” you’ll be fine!
Hope this helps!