Fill prices are rounded in closed trade records.
Fill Price Error
This means when you attempt to analyze your historical trading, it's actually impossible to identify the price you paid for your trade at greater granularity than 0.1%
No fetching of closed orders.
No Closed Orders
The result: An inability to analyze any of your historic activity.
Your closed order information gets deleted if you don't get filled.
Closed Order Info Loss
It's impossible to improve your passive execution strategies because you have no visibility into which trades are likeliest to get filled.
At random, your cryptocurrency deposits can go to the wrong address.
Despite you specifying the correct address, occasionally deposits will go to other addresses assigned to one of your subaccounts.
Nearly all exchanges
There exists no sandbox environment.
And worse, most exchanges will not allow you to have more than one account. Your test trades have to go through your live production trading account.