Maybe i'm just paranoid but as an electronic engineer, mixing units like this leaves me suspicious
You just have to get used to it I am afraid.
The fact that most youngsters these days ie anyone under 45 don't have a clue what 500ft or 1000ft look like.
They tend to do horizontal distances in meters and heights in ft. There are a few specials like rule 5 which is 500ft away from any person etc this is more like a bubble around the aircraft so its horizontal or vertical or a bit of both with a slant.
Then you have speeds in Knts distance in Nm so its a real hodge podge mixture. But once you get your head round it its not a problem.
If you think pilots have it bad you should see some of the mixtures the engineers have to put up with. Metric diameter/length allen studs with imperial threads and profiles with an Imperial key needed for the top. You look at them and measure it and think that will be a M8 FS and then when you get it under a lens its some funny UNF thing.