I believe that for dropdown menus like Scale ratio and Made In dropdowns should be smart stacked. Made In should be able to keep track of which country is most common and sort the countries by current popularity. I hate having to scroll so far for Thailand, a very common country

Dropdowns like Scale should also be able to keep track of what ratios are most common and sort by popularity. But on top of that, the Scale dropdown should be able to keep track of what new ratios that don't appear in the list are common enough to actually appear and self-add the new common ratio to the list. I got some old matchbox cars as a gift and found that 3 of 4 were 1:59 and the last one was 1:56