A poster in the Apple Support Communities (ASC) has pointed out that the Kurdish input source provided with MacOS does not have the mapping officially promoted by the Kurdish Regional Government. For one that does conform to this, go here. Another version can be found on this page.
One of the new features in MacOS 10.14 Mojave is supposed to be "romanized keyboard input for Japanese" or "romanized English input for Japanese Keyboard".
I had a hard time figuring out what this referred to, but thanks to info provided by Magnus Lewan it appears to be a feature making it easier to type English words in the middle of Japanese text. Some explanation in Japanese is here.
Mac is more fluent than ever. MacOS Mojave adds UK English, Australian English, Canadian French, and Traditional Chinese for Hong Kong language options; improved maps for China; and romanized keyboard input for Japanese.
The US International keyboard layout used in Windows differs considerably from Apple's US International PC layout on the option/alt level. You can get a test version of one for Mac which conforms to the Windows layout here.
Among the many 3rd party screen keyboards available for iOS, I recently found one called PADKEYS that imitates the normal hardware keyboard layout, with a number/punctuation row at the top, an option key for symbols and accents, cursor keys, etc. Covers English, Danish, Dutch, Finnish, French, German, Italian, Norwegian, Portuguese, Spanish, and Swedish.
In MacOS 10.13.2, it appears that you cannot switch directly from Chinese/Japanese/Korean to Cyrillic/Arabic/Hebrew/Greek keyboard layouts. In order to get the correct results, you must first switch to US or another Latin input source.
It's possible other keyboards are involved, but these are the ones where I have seen complaints and tested myself.
Hopefully this bug will be fixed in a future update.