jbovlaste should already be filtered to contain only Lojban, and there are, broadly, three types of Lojban words:
cmevla are everything that ends in a consonant
brivla all contain a consonant cluster and end in a vowel
cmavo optionally start with a single consonant, and consist entirely of vowels and apostrophes after that.
So, I think you could filter all cmavo clusters by looking for anything that matches /.+[^aeiou'].*[aeiou]/ but doesn't match /[^aeiou'][^aeiou']/. Contains a non-vowel somewhere after the first letter, ends in a vowel, and doesn't contain a consonant cluster.
At least, that seems like a good start.