You will be fine with ACE, their ATPL test is very basic. If you pass this, you will proceed to the second day which is the Advanced COMPASS test and if you pass this then you proceed to the third day which is sim+interview.
If you make it to the end, they will let you know when they want. It can be one week or one month. And they call you on very short notice, only 2 days notice to do a full medical in order to convert your licence.