I recently replaced my 2014 Prius with a Prime, and so far am very happy with.it except for one thing: if I open the hatch in my garage, it will hit the garage door. The Prius had the same problem that I solved by replacing the stock lift supports with ones with a shorter throw. If I have to, I can probably do that for the Prime though I haven't found the spring force of the Prime stock unit. Some previous posts thought it might be possible to move where the lift support attaches to the hatch to decrease the throw. There are a couple of rubber bumpers that could be removed to expose threaded holes where the you might be able to attached the ball, but no one said they have tried this. If you have, I'd really appreciate hearing about it.
Jim, give it a try and let us know the result. They look exactly like alternative mount points. I was going to take one of the screws out for a look, it appears to take a T30 Torx bit, and mine was previously broken. (I need to buy another.) Keep in mind that the hatch is always surprisingly heavy. Have a prop and a helper ready.