Splitting word across lines

[-JKP-]

The idea is interesting, but is there any line-break-candidate glyph, to begin with?

Even m is not line-ending exclusively, and moreover it's found as folio-ending as well (in which case there's no line to break).

Overall, I have the impression that word-splitting here is something that is avoided 

In Latin, the EVA-m character serves two purposes... it is an abbreviation symbol (for ris/tis/cis) (usually at the ends of words) and also as a sentence/paragraph-end marker. Not every scribe uses it both ways, but some do.