I have read Arcam's early patents They seem quite tight.
I have heard (lost source) that Arcam early patents were like those of the Wright brothers. The patent looked workable, the actual Wright aircraft flew, but subtle misdirections in the patent meant that if you built one following patent directions it would not fly. We know this because for a TV series that is exactly what they did and the meticulously crafted reproduction would not leave the ground.
In both cases later patents filled in the details, giving reproducible results along with a later patent date.
I lack the technical level to determine if this is really true about Arcam.
But it was true about the Wright brothers.
Arcam has lots of patents.
In any case trade secrets may be better protection. No doubt Arcam knows a lot more about EBM than was known 17 years ago.
The real problems are getting EBM industrialized, a system that does not require highly skilled labor and lots of tinkering. And getting engineers to think 180 degrees opposite, about adding rather than subtracting material when they are designing.
Competition might make for quicker adoption of EBM - just as Tesla thinks having other BEV makers will reduce resistance to electrification of the vehicle fleet and thus help Tesla sales
