Thanks for the suggestion.
All languages work the same way, I can not make changes for just one language.
The active text-to-speech engine is responsible for the quality of voice guidance.
The recommended is Google Text-to-Speech which should recognize the units.
100 m, 100 ft, 1 km, 1 mi, …
In the future I may change the voice instructions to have complete words in units.
But it is a lot of work for all [voice language] x [unit system] combinations…
So that Samsung and other text-to-speech engines can work better.