“The crossed 7 is just a way to differentiate it from the 1 when it is hand written.”
Used throughout Europe. I lived in Europe, then worked in the US with many European contacts.
And I used their numbers after awhile, until I reverted to olde fashioned American draftsman precisely shaped figures.
I’ve run a few drafting rooms in my time, and never encountered a competent draftsman or engineer that crossed their sevens.