Chrome Version: 71.0.3556.0
OS: 11042.0.0

In strict mode, all Vietnamese IMEs require diacritic triggers to immediately follow the letters that need diacritics. 

There's a popular flexible diacritic trigger mode where diacritic triggers can be typed "later" (towards the end) or "earlier" (towards the front). The IME is supposed to place the diacritic on the most linguistically correct letter as per the orthography at every step.

Currently "Vietnamese keyboard (VNI)" only implements the flexible mode for tone-mark diacritics (acute, grave, hook-above, tilde, dot-below), but not letter-modifier diacritics (circumflex, horn, breve, cross-bar). The mode is incomplete and hence inconsistent.

Minimal examples:
type "nguyen64" -> expect "nguyễn", currently get "nguyen64"
type "tran8g1" -> expect "trắng", currently get "tran8g1"

NOTE: This feature should work correctly for *all* cases as per Vietnamese orthography, with regard to diacritic placement and syllable structure, not just the minimal simplistic examples above.