My M20 2020 Gain came with a small bike controller that appears to be identical to the Wahoo Coach Smart. According to Wahoo, the Bolt and Roam are all compatible with the new eMTB 2020 bikes that have Ant + Lev. The specs on the 2020 Orbea gain includes a spec line that reads Display: OC Ant +Lev. This must be the bike controller I have. There is no mention of Wahoo on the controller or the Orbea Specs, but it looks identical to the Wahoo Coach Smart and it's menu operates exactly the same as the online Wahoo Coach Smart manual indicates.
This leads me to believe that the Wahoo bike computers have the best chance of straight forward compatibility and they support both Ant+Lev and the new low power Bluetooth. What I can confirm is that this is indeed the fact. Other then vague reference by both manufacturers to each other, online tidbits from people who have tried it have had limited success. I'd like more people to jump into this discussion but as you see, just crickets.
The OC controller I have displays speed, mileage and ride time and also allows the assist levels to be changed with the lower buttons, so I'm thinking Wahoo should be the best option as I'm pretty sure Wahoo OEM's their Coach Smart to Orbea or eMotion Bikes.
The few who say it works say they can see assist level, but not the speed and they are having difficulty finding a way to change the assist level. Personally, I'm tired of using my phone to follow Ride with GPS maps, putting my garment edge into my pocket to record rides, and changing assist levels on the OC controller when a Wahoo Bolt or Roam could do it all.