Analysis of the stability criteria for the density maxima generated during the outburst in the FULL model. Top three panels: temporal evolution of the surface density Σ (panel a), the parameter κ²/Ω² (panel b), and the vortensity q (panel c). These are shown as snapshots during the time frame starting from the ignition of the burst (t = t_TI, blue line) until the first density bump has reached its outermost position and κ²/Ω² becomes positive (brown line). Additionally, the pink line represents the disc at t = t_quies. The dashed green line in panels b and (b₁) indicates the halfway-to-Rayleigh stability threshold. Bottom three panels: Same three quantities, but zoomed into the radial region where the first density bump is located. The colour-coded time frame begins at the moment when min(κ²/Ω²) > 0 and includes the transition from instability to stability according to the halfway-to-Rayleigh criterion, reached at t = 3877.7 yr (orange line in panels a₁, b₁, and c₁ and in the colour bar). Quantities in panel b, (b₁), panel c, and (c₁) are depicted on a logarithmic scale with a linear transition around zero, indicated by the grey shaded region.