Blast procs consist of two distinct status effect components – the normal stun on recovering victims which is displayed by the icon and the knockdown which isn't depicted – that can stack for additionally increased damage, up to 720.58x with the procs listed above.
The damage increase from the knockdown lingers briefly longer than the one of the depicted icon.
Note that conditions or abilities that prevent knockdowns (e.g. Bastille) will hinder the second component from increasing damage.
To achieve a high amount of distinct status procs, it is advised to use melee weapons that feature high attack speed with high base status chance and all physical damage types like the Lesion or Glaive Prime.
For complementary ranged weapons, it is advised to use weapons that feature high fire rate or AoE with innate elemental status, such as Staticor or Pox.