yeah, that'd HELP mentioned you're rotary. I'm rotary FAA CFI and since it's on generic section of forum and you haven't stressed it, I wasn't giving the info you subsequently received. Yes, class and category (with exception of the glider review possibly done in fixed wing/fw sim). I'm not heli CFII (yet) and fiddle with fixed wing flying bit, too, so for me it's worth keeping in mind any limitations to category/class, as you see now.
I'd have to look up the specific regs, but
having IGI rated instructor could solve this, although still needs a/c or sim in relevant category. IGI is simple written pretty much what CFII theory written is (if one has done FOI written) but
AFAIK, most people don't bother since CFI or CFII includes sim teaching privileges. Just had quick glance and yes, IPC can be done by IGI holder as well.
T2000, maybe doing IPC in the aircraft if they pretend it to be somewhat fancy and expensive SIMULATOR (say rated CFI for the a/c but not the student, or being other category CFII and student priv/comm rated in the a/c),
but I still can't see how the relevant class/cat can be circumvented by this. So yeah, they did it agains the regs if you heard of it. Not saying it's right, if it's happening. Honestly, I've heard WRONG interpretations of regs or dwelling on OLD system (if there ever was something that'd allow some stuff) and not in line with regs nowadays or recent years. I'm not blaming instructors who don't self study or doublecheck regs to ensure they're following the laws/regs, I myself don't revisit general stuff regularly, but potential legal minefield situations really OUGHT TO BE investigated. Or the loopholes are exploited till the FAA 'notice' and close them down with Part 61, 91 etc update. Instructors aren't walking CFR nor lawyers etc.
Can anyone give reference to PROHIBITION of using non-N-reg a/c if the local/national laws of country of registry/airspace are OK with it? Ie EASA rated FI in EASA country aircraft or with private owner and IPC in his a/c.