Arrayformula on column header

I have a sheet with an ARRAYFORMULA on the column header. But I want to have the formula as an ARRAYFORMULA because when rows are added to my spreadsheet I don’t want to have to require the user to copy/paste a formula.

I’ve used this before, and glide hasn’t stable with ARRAYFORMULAS, I think because the column names are changing. What are best practices with these?

Use this technique:

+1 for @George_B’s method