Yup, the hyphenation patterns used by CoolReader (the application used for reading FB2 files on the V3) are atrociously bad. It should be possible to improve things by creating a folder named "crengine" in the root of the SD-card and put a .pdb file containing better hyphenation patterns into that directory. I'm using English_US_1252_hyphen_(Alan).pdb which torbich linked to in
this post, with the language set to "en" in the book, but without much luck:
By my estimate, about one half, but surely at least a third, of all hyphenations are wrong, sometimes stupidly so: the thing loves to hyphenate words one letter before a mid-word dash, thus e.g. hyphenating mid-word as (mi)-(d-word).
F**k this! LaTeX had rather good hyphenation support in the mid 1990's. The patterns were conservative in that they didn't always hyphenate when they theoretically could have, but at least it was
exceedingly rare to encounter wrong hyphenation. That problem was solved then, there's absolutely no reason it shouldn't be solved now. :-(