“…Since then, an explosion of works has analyzed a variety of related interfacial instability problems in "nonstandard" Hele-Shaw configurations (Morrow et al, 2019), both fixed geometries (Dias and Miranda, 2013, Al-Housseiny et al, 2012, Hu et al, 2016, Jackson et al, 2017, Grenfell-Shaw and Woods, 2017, Bongrand and Tsai, 2018 and those with flow-driven geometric changes (Pihler-Puzović et al, 2012, Pihler-Puzović et al, 2013. Further variants on the same problem also include controlling the injection flow rate (Dias and Miranda, 2010a, Dias et al, 2010, changing the permeability by adjusting the structure of the porous medium (Jackson et al, 2017, Rabbani et al, 2018, Brandão et al, 2018, applying an external force via rotation of the geometry or through a magnetic field (Carrillo et al, 1996, Alvarez-Lacalle et al, 2003, Miranda and Alvarez-Lacalle, 2005, Anjos et al, 2018b, changing the fluid properties through the viscosity ratio (Anjos et al, 2017), using non-Newtonian fluids (Vlad and Maher, 2000, Lindner et al, 2002, Tordjeman, 2007, Boronin et al, 2015 or even adding a suspended particulate phase (Xu et al, 2016, Kim et al, 2017.…”