You should absolutely do that (I tell my team to inform me if what I'm asking doesn't make sense.) If I'm coming to someone with a request, it's because I think they're the right person to address it. Just tell me if I'm off-base.
FWIW, I encourage everyone to not care about the hierarchy, so that may not work in every place.
In my experience, this is not true at all. But, as you say you don't have direct experience to come to this conclusion, may I ask what makes you think this?
My personal theory is that it's connected to job security and how big personal problem it is to lose your job in a layoff. If you get laid off in Europe, your health insurance is paid from public budget now and you get several months salary from your employer. If you worked for a big name, it may be six months or more. If it was a small startup, you get at least two months.
Our US colleagues always made more money but also were more afraid of losing their jobs. All of that said from the IT perspective. I'm sure being a coal miner and getting laid off is much worse.
No fan of Suella Braverman, but she got fired not because of what she said, but because she publicly went against hierarchy, which seems to be a terrible offense. Which in the UK it probably is.
You could have a percent of each sprint dedicated to one-offs, but then are they really one-offs in the colloquial sense?
The smaller the team and org, the easier it is to handle the one-offs (imo), because we can more directly connect the request to tangible impact more often. At the very least, in a small co your manager (or C suite executive) would easily back you up as the engineer if other executives were questioning output or something etc etc
In larger orgs the extra communication burden makes the one off requests more expensive