Roche lobe response to the dynamical stability of mass transfer. The donor star is able to recover its hydrodynamic equilibrium while remaining within its Roche lobe with a mass ratio q = 0.287 ± 0.047 to different accretion efficiency values from ϵ = 0.0 to 1.0 (yellow triangle). Blue dots represent other well-studied DPVs. The dashed green rectangle spans from the minimum to maximum mass ratio of the DPVs known to date.