So far this has worked well enough, the phone or charger do not heat up and I haven't noticed faster battery drain or anything like that.
However, charging takes about twice as long, so instead of 60% in 30min I get 60% in 1h. This is also the case when I use the cable with the original dash charger mains plug. Having gotten used to the incredibly short charging time, this is a major drawback, but nothing I can't work around. Also, I needed a way to charge my phone after loosing the only compatible cable, and this arrived much faster than anything ordered with OnePlus could have.