Have really enjoyed catching up on the UDH news from the last year or so, although a bit sad that ongoing development has run into a few problems.
Best wishes to Leif and Sindre.
From what I can see - as a believer - the major challenges for a large scale commercial system are (i) reaction upscale, (ii) designing a shielding system to deal with (and hopefully capture) all the high energy neutral particles generated, and (iii) power generation.
If decay particles could be forced to be charged, that would help a lot...
Given the current status of international relations, I suspect that “closed book” development by a major backer may be the most realistic path to realisation of positive technology potential.