Yes you shouldn't.
Many times they are registering your new domains manually, hours after you are giving the order.
You may receive an email 2 days later that something failed.
In the meantime, the domains may not be available anymore...
Also, some times they are coping owners data from your former registrar, while the domain is under privacy protection.
So your domain's owner's email may be something like "
[email protected]".
And to change owner's email you have to send them pdf files, filed and signed + Passport, to that you claim you are the owner...
Also they have no bulk function, or domain lock function, and their live chat is the worst