I'm a big fan of Korean food too
The BBQ is the best! The other food is probably lovely too, but the BBQ is so good I rarely stray from there.
I was thinking that a trip for them to come here might be good too, we have a lot of breweries and I'm sure a bunch of them would be willing to host. We also have a big Asian population, and I know a bunch of native Koreans through my kids' TKD school, so if their English isn't that great I think it would be easy to find a translator.
My questions for them would start with what ingredients they are using. Types of malt and manufacturers. I'm guessing they are not using Crisp MO to make their beers? The hops are probably different too. And since you said your beers don't scale up well (not really surprising), are your ingredients different? What malt CAN they get?
What size is their system? Do they have a pilot system?
Have they had the water tested?
What kind of beer do they want to make?
For them to get the most out of any consulting, I think they'd need to answer those questions up front. It would also be good for them to send samples of their ingredients to the consultant for test brews and recipe development. Some of it could be done prior to the first trip, I think that would be helpful for them.
From some of your previous posts I seem to remember the ingredients could be a problem for them, plus their willingness to use hops in the proportions typical for hoppy US beers.