Unfortunately no - it's been on our to-do list for a while now but it's complicated enough that we're having a hard time fitting it into our schedule.
However, since you're a jailbreaker, the file containing Pleco's preferences is stored in its document directory under .pleco/PlecoPrefs/Engine - copy out that file, then copy it back post-jailbreak (there are ways to do that even on a non-jailbroken phone) and you should be all set.