Nest CHOOSECOLS inside UNIQUE to extract non-adjacent columns, and use INDIRECT for interactive header dropdowns.
Row precision vs. Aggregation errors: MAP is the best way to use "greedy" functions like AND or OR in a single, dynamic ...
If you are working with Excel spreadsheets or workbooks, juggling multiple tables of data, at some time you might need to combine them into one. Rather than spending hours manually copying and pasting ...