Interesting, now the whole issue is where to get a "Qualified" instructor ( More than 500 hours instructing time, am I correct )? to pass the test.
In the same place you would get an instructor to teach for any other instructor certificate.
And those 500 hours instructing , need to be in appropriate field (Aero/Mountain/Towing) ???
No, where did you get that idea?
If not what happens if the "Qualified" instructor has no experience in those fields ???
Since a person may not instruct (FCL.915(b)(1)) or examine (FCL.1000(a)(1)) for any qualification unless he/she holds that qualification, this should not be a problem. You simply need to find an instructor, qualified to instruct for the issue of an instructor rating, who is also qualified to instruct for the aerobatic rating. This will apply to many of the current 'FIC' instructors and most FIEs