Quick update for those who are curious about eR9. I ordered no box and no battery. The package itself is well done.
I have bad news and good news. Let me start with the bad news to get it over with. After lots of debugging, I found out that one of the cables (short one for FD) is faulty. Initially, the front derailleur (FD) intermittently stops working and I thought it was the FD that was faulty. It turned out, connecting that cable to the rear derailleur gives the same problem, and so I concluded that it was the cable. I have contacted LTWOO store from which I bought the set and now waiting for a response.
The good news is all other components are really well-built. I was really impressed. The small hood size feels amazing on the hand. Buttons are very clicky and feel solid. The shape and reach of the levers are just perfect for the size of my hand and fingers. The texture of the rubber hood feels slightly different from Shimano, feels a little less smooth, but I like it. Since rear derailleur is fine, it shifts quickly and there is barely any noticeable delay from the moment the button is pressed to the shift. I can confirm that the trim option is there, but no auto-trimming (they removed this for patent reason).
I can also confirm that LTWOO has now enabled 10 speed option on the application. The eR9 set came out to be just slightly lighter than the quoted weight by LTWOO. See the breakdown below.
I have not installed the set on the bike yet. I was bummed that a single cable prevents me testing them on the road. This will have to wait a little while.