May axion clusters be sources of fast radio bursts?

Fast radio bursts can be caused by some phenomena related to ‘new physics’.One of the most prominent candidates of the kind are axion Bose stars which can engender bursts when undergoing conversion into photons in magnetospheres of neutron stars or during their collapse. In this short research note an importance of three observational criteria is outlined, namely total energetic, $\mathcal{O}$(ms) duration and non-monochromatic shape of the spectrum. It is shown that it is impossible to meet these criteria in simplified models of axion-neutron star interaction scenario and thorough investigation of more complex models which involve back-reaction and non-linear effects are needed in order to explain FRBs within this scenario.