Thread titles phrased like this work as click bait. There's a tiny but appreciable dopamine spike when being asked to share one's opinion. An informed opinion is irresitible. Which is essentially an opportunity to talk flatteringly about ourselves - a real pleasure.
When I first started out - poorly trained in a fast track centre and anxious about everything - I used to drill slightly too big a hole (25mm) rather than risking the pipe getting stuck (i know - jeez - how would you get out of that terror!!?), would never lag or sleeve the pipe, would use integral d/c valves rather than separate and would pipe it in any way I thought
would get a good fixing on the wall and look ok, running upwards not unusual. I even remember one time someone wanted isolation and there was "no room" inside so I put one on the short run to tap outside.
Now I follow the majority advice outlined above.