Short answer: I think so.
Long answer: It should be, the worst thing that can happen is a server crash. Be prepared that there are many differences between these two versions. With 0.6 MySQL is introduced and much other things changed, but feel free to try out!
By the way, LUNI is coded in C++ and MySQL. LU uses RakNet, so take a look at that as well.
As long as you hope, you can.
P.S: We have a community chat on skype, add XYQuadrat to get in.