You know the one thing Imperial is far better for is building supplies… it just doesn’t translate or make any sense in Metric. I am pretty good at eyeballing and rough math.

ask me about my cement patio steps that ended up absolutely perfect and to code for rise/run, square and level, based on… “that looks about right, I still have to put the cladding on it, it will be fine…” I shocked myself almost as much as DH when I checked them (I was expecting acceptable-ish, he was expecting
total failure “You didn’t freaking measure
ANYTHING! Are you mad???”)
I’m pretty annoying myself in bouncing between systems, a product of my age. Weight I will use grams, then ounces down to a 1/4 oz, pounds, especially for veggies, but for selling meat and fish products it’s all in grams and kg. Liquid measures I will generally use litres for fuel etc, but can usually do the gallon conversions, quickly. Cooking is of course in Cups, distance is mm, then 1/8+in inches, feet, then meters and kms.
However the two Most frustrating ones for me are temperatures because the Fahrenheit/Celsius comparisons make NO sense whatsoever, and the USD to CAD or anytime I need to figure out two or more of the numbers together!