I don’t think I’ve ever heard someone say that at the start of a phone call but it’s common when communicating with two-way radios like:

“Alex for John, over”

“Go for John, over”

“<whatever Alex needs to say to John>”

I mostly heard that when working in large retail stores, usually the walkie talkies have an end-transmission sound que so we didn’t actually have to say ‘over’ at the end

I have Hatchbox PLA in most colors and it works fine for me. If I want to make something more rugged I use eSun PLA+. I also have a couple spools of Tecsonar multicolor PLA filament and those prints always come out looking great!