I agree. Korma for that number should be fine in bulk to a certain extent. Might not be perfect but I reckon you'd get away with it.
My introduction to BIR was 5 or 6 years ago with the ebook by David Smith, Curryhouse. All very simple stuff, but a great starting point to help get your head round the basics before moving on to experimenting more.
One of the things he stresses is that the recipes are designed to serve 2-3 people and that they can safely be doubled but no more than that.
I thought "what a load of nonsense" and stupidly quadrupled what was a perfect recipe with disastrous results. It makes no real sense as logic tells you 4 times the people = 4 times the ingredients, but although that may work with a Sunday roast, it certainly doesn't with curry!
Good luck with your Korma ... don't beat yourself up too much at the fact you're limited to Korma. Certainly not something I'd normally choose, but it can be really nice
