Blackflame unique doesn't allow contagion to spread ignites

Based on the wording of the contagion spell, I was expecting it to be able to spread anything that is a debuff and deals chaos damage over time. Based on the definition of a debuff, ignite should be a debuff since it deals damage, and with the blackflame unique it's dealing chaos damage over time.

Unsure if I'm missing some interpretation but seems to me like this should work and in my testing the ignite does not spread to other enemies when the first enemy dies.

the key is that 'enemies take ignites fire damage as chaos damage'. Technically, its still a fire dot, it just so happens to be that the enemies take it as chaos damage. This is why things like fire dmg and ignite magnitude increase the damage still, but increases to chaos damage do not. Think of it as being on the enemies side of things. As far as contagion is concerned it is still ignite (fire). Truly a shame though, I feel like chaos witches have very limited kits. Hopefully the 3rd ascendancy makes things a little more interesting.