It's always been a touchy topic, this one. There used to be a board editor around for a very limited time back in 1999, I believe. It was created by a guy who went by the name NOPeR, but it wasn't an official board editor, though. Considering that DX-Ball 2 was (and still is) distributed as shareware, I suppose a board editor was not really in LDA's interest, in spite of an inevitable demand for it, as time has shown. However, in cooperation with NOPeR, they did work on a solution to the problem. First of all, they set a restriction to the game that would limit the number of user-created boards one could play. This was, of course, to protect their property of sales. Meanwhile, the solution that was being worked out was intended to let owners of Board Pack 1 be able to play user-created board-sets with no restrictions.
While the issue eventually had been resolved in terms of programming, things took a different direction for LDA when the family-driven company lost their founder, president and lead programmer, Seumas McNally. The final decision thereafter was to strip the game of any support for user-created boards, and the board-set editor was thereby discontinued.
Times are different now, of course, and Longbow has a come a long way since. But the subject of a board-editor is still something that has remained underground over the years. If you do some clever searching, you might just stumble upon NOPeR's DXBoard. But it will only work with DX-Ball 2 version 1.2.