Yea you are right, it would be best to wait and see the reviews and then decide if you will buy it.
Building your own is always and option but like @
Magnetic said it is at your own risk but also has its own perks
I have heard about custom made chastises as well, like you give them the measurements as instructed and they send the product after custom making it, as i heard it is a bit expensive though, but maybe it would be good with something like this that is already expensive so adding a bit more so it custom fits would not make a big difference