The virtual absence of XUV with Helium appears to be a strong reason for me
Why should Helium not do bremsstrahlung when Hydrogen does?
I'm not really sure. Perhaps the helium is more effective at thermalizing the accelerating electrons in transit? At any rate, absence of knowledge for why hydrogen would be a factor versus helium is not a sufficient basis for going along with a conclusion that hydrinos were the source of the broadband spectrum.
My assumption is that the hydrogen ions are not what cause the bremsstrahlung, but the electrons themselves, after they've crossed the gap. There is an argument against this:
The influence of electrons triggering the discharge (electron gun) was also eliminated as the source of the continuum radiation. The applied pulsed voltage to drive the plasma was increased from -10 kV to -15 kV in sequential runs to determine any high-energy electron effect on the spectral profile. No effect was observed; thus, high-energy electrons were eliminated as a possible cause of continuum radiation.
I don't think this reasoning is good. The electrons in this case will have had significantly more energy than in live runs, and hence would not necessarily yield the same spectrum.
How much does replication , bremsstrahlung checks cost?
I'd estimate $50,000-$100,000 throwing in the hire of facilities/technicians
I think the cost might be out of the range of crowd funding for a few years
I don't think it would cost a researcher with adequate facilities this much. There would just need to be interest on the part of someone with access to comparable equipment. Admittedly, such interest might not be easy to come by.