I just upgraded the server to 1.4.2!
The upgrade includes SEVERAL beta/dev version plugins.
I will be updating everything continuously as new versions of the components come out, but from my testing all should be fine.
If you find a bug or exploit that you can reproduce, please post here.
Regarding building the wither, I now disabled that in all worlds. The question is where to enable it so that beacons can be made.
I can enable/disable the wither only per world, not per lot. Shall I just enable it in the nether?