tado stand accessory isn't compatible with tado Smart AC Control
The stand accessory is marketed as compatible product, there is manual entry how to use it with ac control and it is sold by some retailers as bundle.
Despite that it obviously not designed to work with Smart AC Control - if you put it the way suggested in the manual the device will fall off from the stand every time you touch it (or move on the stand if you stretch the wire). It's obviously need suitable backplate for proper attaching.
My suggestion: tado should design and produce (or 3d print if we speaking of small quantities) suitable backplate for Smart AC Control and send it to every person who bought it as a bundle with smart ac (or by request if it's hard to track).
If someone in tado management disagree with my opinion - you should just try it by yourself. Device with such control should be attached to the stand, not just lie on it (or hang on the wire). It shouldn't be sold that way, but at least you have opportunity to correct this mistake.