In a program with users spanning from basic users with limited knowledge to super users with specific needs and detailed knowledge, we need to offer the option to select and deselect among elements out of a group of 15-50 elements.
Most users will not know the meanings of the choices and will just need all of them selected. I'm not sure if it's optimal for them to see all the options (it's basically a bunch of company names - will they be impressed or intimidated?) or to have to click on something like "specify which companies to include" that then shows the options.
Or is there some sort of hybrid approach where the size of the options are indicated ("cards" that show first option and indicate depth of stack?) that can then be expanded to show all options (stack of cards is laid out into grid) when desired?