  We show that coherent inflation, namely quantum dynamics generated by
inverted conservative potentials acting on the center of mass of a massive
object, is an enabling tool to prepare large spatial quantum superpositions in
a double-slit experiment. Combined with cryogenic, extreme high vacuum, and
low-vibration environments, we argue that it is experimentally feasible to
exploit coherent inflation to prepare the center of mass of a micrometer-sized
object in a spatial quantum superposition comparable to its size. In such a
hitherto unexplored parameter regime gravitationally-induced decoherence could
be unambiguously falsified. We present a protocol to implement coherent
inflation in a double-slit experiment by letting a levitated microsphere
traverse a static potential landscape. Such a protocol could be experimentally
implemented with an all-magnetic scheme using superconducting microspheres.
