Interesting piece, sadly I don't think this is all that unheard of.
That said, what all are you guys being taught is a "large-bore" IV? When I went through paramedic school I was taught either a 16g, or 14g respectively.
The other day I brought a standard ALS patient in to an area ED with an 18g locked off. The triage RN commented on how most everyone else that brings in patients is putting in 20's (medicals); she seemed pleased it was an 18 as this particular ED likes drawing labs from our IV's. I was taught 18 and down for medicals. If they can fit, my STEMI/ stroke alerts get 18's locked off, if not, 20's are fine.
Typically I don't ask the patient, TBCH. I can gauge it (pun intended) by looking at their vascularity. If they give the infamous "butterfly remark" I do my best to honor their request, though.
I'm a bit different about my IV's, and their placement though, as my wife often hounded me about technique (still does) all through paramedic school.