Muon-catalyzed fusion: muon number problem

I recently read a paper "Meson-catalyzed fusion in ultradense plasmas" (it is behind a paywall: only subscribers to Physical Reviews E can read it) that claims that muon-catalyzed fusion in substances such as warm-dense matter lead to cycling rates many orders of magnitude greater than the rates shown for other scenarios. They also claim gains in the range of ~10-10000. I should note that the gains here are the ratios of the energy output to the energy required to produce the muons. However even if these gains are correct (and I am skeptical), there is another issue that I don't see anyone mention when discussing the potential of using muon-catalyzed fusion (MCF) as a power source: muon number. If we wanted to use MCF in a practical power plant, I am quite sure that the number of muons we would need is unobtainable at the moment Delivering the world’s most intense muon beam. Is there something I am missing that negates the problem?

Despite this, it may be possible to use MCF to spark traditional inertial confinement fusion (ICF), but the only advantage that this has that I know of is that it would be impacted less by instabilities compared to normal fast-ignition ICF.