I found out the hard way there is a gap in the way Broadsoft implemented feature 52261 (Trunk Group Pilot User) in R14.SP4 and higher. The issue is when activating 52261 all of your primary Trunk Group number will now require Call Waiting to be assigned manually to the Pilot User. Prior to activating 52261 the number associated with the Trunk Group is considered a virtual user and ther is no limitation as to how many calls the virtual user can receive. As soon as Trunk Group Pilot User is turned on, all Pilot Users will only be able to receive one call and the rest go to busy. You will have to manually assign Call Waiting to every Pilot User on your system. This could take anywhere from several minutes to several hours.
Fortunately Broadsoft is releasing an AS patch for R14.SP4 and higher to address this.