Untried hunch: Haven't diddled with MCE as much as I'd like to have (possibly should have) but if the problem is that your worker children are inheriting too much context, then rather than pulling in Inline::Java in the parent you might try pushing that out into a separate module which you then require in your on_start handler for your MCE::Hobo workers. That way you're going to be sure that an separate JVM instance and all its associated plumbing is coming up only on the child process side of the fork.

Edit: Derp, I do need to play with MCE more because apparently (re-?)reading the MCE::Hobo docs the on_start callback is called in the parent after a worker is started. Possibly instead then do the require in the sub you pass to the create method instead and that'll still keep it done only in the child.