Can asteroid-mass primordial black holes be all the dark matter?

For primordial black holes with masses $M = 10^{17} \text{ to } 10^{22}\,\mathrm{g}$, no current constraint excludes a dark-matter fraction $f_{\mathrm{PBH}} = \Omega_{\mathrm{PBH}} / \Omega_c = 1$. Determine whether $f_{\mathrm{PBH}} = 1$ is allowed anywhere in this window, via detection (Hawking evaporation products at the light end, femtolensing or microlensing of stars and gamma-ray bursts, dynamical capture in stars) or exclusion of $f_{\mathrm{PBH}} = 1$ across the whole window for monochromatic and extended mass functions.

Microlensing surveys and MeV $\gamma$-ray observations sensitive enough to probe $f_{\mathrm{PBH}} < 1$ throughout $10^{17}$ to $10^{22}$ g.