Ebay SpeedPAK Economy from Japan

I made a post a few days ago regarding the huge brokerage fee that a buyer had to pay in the US to UPS.
If I understood well, the brokerage fee is only paid by private companies through their own broker which is why I should wait until Japan Post resumes sending parcels to the US as they are using USPS which is government-owned company and thus don't have to pay such fees.

Going back to the title, I found something on ebay called Ebay SpeedPAK economy and found little to no information regarding the rate, or which company they use after it lands in the US.

I found this website but for some reason, it only shows the rate from China even though it's also available from Japan through a company called Orange Connex.

Is there anyone with information as a seller or even buyer side regarding this method ?

Since it's an ebay shipping method, are the import fees included in the price ?

Any information would help, otherwise, I will just stop selling items to the US as proposed by many of you guys in my previous post (Btw thanks a lot, I really appreciate everyone's help)

Edit: I'm a seller from Japan

Edit2: As mentionned in one of comments in this post, Orange Connex doesn't allow non-Japanese nationals to use their services so I basically cannot use this service at all