I don't know of any language that has this sort of metathesis in vowels other than Hellenic, and since this has gone unanswered for over five years, I suspect there may not be one. But there are a few related phenomena which are worth mentioning.
Compensatory lengthening is a process that happens in several languages (including Ancient Greek): when a consonant is lost for any reason, the vowel before tends to be lengthened. For example, English "night" originally had a short /i/
; when the /x/
after it was lost, the vowel lengthened, giving /i:/
(which became /aj/
in the Great Vowel Shift).
More relevantly, the Littera law ("inverse compensatory lengthening") is a sound change that happened in Latin in the early centuries BC. It's named after the word littera "letters", from earlier lītera; in certain environments, the sequence V:C
became VC:
. This happened with sonorants as well as plosives, such as flāma > flamma "flames".