As a Ivac2 DP member. I must say, Creating an FIR on IVAC2 must be a very simple task. This depends to the access of RL datasources such as AIP etc. With XML its pretty easy to code as you dont really need to understand XML as i would use a pre defined method. This makes it easier for me. Currently for IVAO i am developing the sectors for WSJC | DGAC and UGGG FIR
Yet again you do have a point. The usage of IVAC2 is initially complex but as you put more hours into it, it becomes easier to use.