The Speedo TR5 v2 treadmill has bluetooth connection with the FitShow App and it´s also compatible with Kinomap, which controls the treadmills elevation according to the terrain, that way, it’s totally feasible to zwift to do the same.
Doing a quick research, the treadmill implements a open iFit platform with 4.0 bluetooth that provides information of distance, speed, calorie consumption and other data.
Thanks Ana. I have the same treadmill and make the tests with FitShow. But with the Zwift don´t work.
Same here @Gustavo_Simon, with FitShow I can control my Speedo TR5, but while trying to pair with Zwift, it doesn’t find the treadmill as a connectable device.
I think you should vote on this issue if you would like to get it implemented by Zwift in the coming versions. I voted already. 
Do you have feedback on this treadmill?
I’m considering one for some small runs (1hr duration maximum, 5m/km pace average, 1.76m height). It’s a good choice?
The store offered one TR4 for me, but I’m not sure it would be enough for this usage.
Thanks.