I was thinking along the lines of Space, just simple, real ingredients.  You can use real grated Parmesan/Romano cheeses mixed with garlic, and salt.  Make a cinnamon sugar blend.  Is there a packaged taco seasoning that is safe, and you can use?

Or just a small bottle of olive oil, some himalayan pink or smoked salt, and other specialty herbs?  That's how we dress our popcorn. 

Love your idea!

Just googling, all the chile lime seasonings I've found have soy-free ingredient lists, but the garlic parmesan has soy oil.  I have no clue about cross contamination or whether soy oil are problems for your family member.  Maybe making your own would be best?

Here's one for garlic parm
http://www.food.com/recipe/parmesan-garlic-popcorn-spice-mix-143455

and chile lime
http://spicedblog.com/make-your-own-citrus-sea-salt-blends.html

GREAT idea, BTW!

No advice, just wanted to say that is an awesome gift!!!

I am giving sisters's family a cool popcorn poper for Christmas. I thought of giving them some flavored toppings as well but need soy free are there any prepackaged popcorn seasonings out there that are soy safe.or  rather I should say you trust.  Was looking for things like Garlic pamagian, or Chili lime.