I was told this can't be done because the software would not allow it!
Methinks someone is fibbing to you (or just doesn't know). I've always gone in and set my own parameters: dry weight, heparin rate, disabling the BP cuff, etc. I've never had a problem.
You are right.
The goal can be increased to over 5 liters. I checked it today.
Now if I could just find out how to increase the UF rate to above 2 l/hr!
As for the reason why they told me it could not be done, your guess is as good as mine.