As noted elsewhere, all attested Danian words ending in a short primitive vowel had that short final vowel vanish. In many cases, a long primitive vowel vanished as well. The example ᴹ✶kuʒnā > kogna > cogn indicates these long vowels shortened before vanishing (Ety/KUƷ), as was the case for other Eldarin languages like Noldorin and Ilkorin.

Two waves of vanishing: There is some evidence that the loss of final vowels occurred in at least two waves in Danian. The word Dan. Edel < ᴹ✶edel- probably ended in a short vowel (Ety/ELED), but it did not undergo the Danian syncope. However, Dan. alm < ᴹ✶ÁLAM (Ety/ÁLAM) did undergo the syncope. One possibly explanation is that the primitive form of alm ended in a long vowel that was not fully lost until after the syncope, which is why the syncope occurred for one word but not the other.

Transformation to final [a]: There are also examples of primitive long final vowels becoming [a] instead of vanishing. Most of these examples likely had a long final [ā] that survived as short [a], but there are at least two examples where a different long vowel developed into a short final [a]: ᴹ✶khrassē > Dan. hrassa and ᴹ✶ñgolodō > Dan. golda. In the case of long final [ō], it may be that the final vowel first shortened to [ŏ], and then changed to [a] as part of the general rule that short [ŏ] became [a] in Primitive Danian.

The case for long final [ē] is less clear. There are no examples of [e] becoming [a] in other positions in Danian words. In fact there are only examples of the opposite change: short [a] becoming [e], perhaps after initial clusters of [s] with a voiceless stop. It seems that the change of long [ē] to short [a] was unique to final vowels. There was a similar change of long final [ē] to short [ă] in Western dialects of Proto-Germanic (ref/@@@).

Preservation final [a]: Assuming that long final [ē] and [ō] merged with long final [ā] in a short final [ă], the result was sometimes lost and sometimes preserved. The [a] was preserved after the clusters [ld], [nd], [nn], [ll], [ss] and [rm], though the last of these examples was in the rejected word Dan. garma. The preservation of the final [a] could also be related to patterns of stress in Primitive Elvish words. Given the small number of examples, it is difficult to guess what the pattern might be. The developments of final [a] in the Germanic languages that inspired Danian are sufficiently different that they do not provide any clear hints.