Okay, so if you wanna go down that road (pun intended), the best way would be to order a ER9 group and a spare EGR RD and link them together.

And if the RD fails for whatever reason, you still have a spare ER9 RD to use until your EGR replacement arrives 

Just to confirm though. The EGR battery pack only has 1 cable port. You'd need a 2 cable port battery pack. Also is there any confirmation that the EGR RD will talk to an ER9/X FD if hooked up together?

this is how they work together

Just to confirm though. The EGR battery pack only has 1 cable port. You'd need a 2 cable port battery pack. Also is there any confirmation that the EGR RD will talk to an ER9/X FD if hooked up together?

Because they are identical. In evey detail, including hardware supplied with the frame. These stores in Ali, are reselleres.

That begs the question… who is the original? We should from them! Lol.

I checked it for you, mounted rear derailleur eGR front eR9 works together, gear change works RD reacts to the right brake lever FD reacts to the left brake lever so the sets can be swapped. A large beer is due

Incredible! You're now the hero of this forum. Seriously cool of you to drop this info!!!

Edit: On a more sobering note, surely you run out of derailleur takeup for a wide range cassette + 2x chainrings. But, even if you're somewhat limited on the number of gears or functional configurations of your setup, simply being able to mix/match parts to get a working groupset together is incredible value. I can't fathom why Ltwoo wouldn't advertise (or even mention) this fact?!

For me, personally: Right now I have an eGR. If I wanted to turn my 1x gravel bike into a road bike is swap my crank, swap my cassette, and clamp on a front derailleur. Boom. Now I've got a 2x road groupset. Hell, I think I can get 2x chainrings for my current crank, so really I just need to bolt on a new chain ring, clamp on a front derailleur, and swap my rear cassette and I've got an entirely new groupo.