I was an ER scribe for 2.5 years. I asked for LOR from 2 docs. One doc I had gotten to know after about a year (maybe 8-10 shifts with him?) and he literally had it done the next day after i asked him, he let me read it and it was a really kickass letter.
The other doc I had gotten to know pretty well also and asked a couple times, he agreed to do it, I waited a few months, asked again, waited a month and just let it go because he clearly wasn't going to do it/kept forgetting. I think a big part of it was that I was using interfolio and he was older (65+) and just had no clue how to do it. I tried explaining it but I think he just dgaf about learning it lol
All our chief scribes were pre-med or pre-PA so no idea why you would ask them for a LOR, unless it's for something other than med school