Self ignite ? legit?

The well know Maehlin’s Hubris Gloves convert bleed chance to ignite chance.
But Exsanguination Node for spirit plague never talk about chance. Just apply 1,2,3,4,5 stack of bleed. So why is this convert?
And the Double Edge Scythe node from harvest talk about self bleed chance but is not convert.
Do you know if develloppers talks about it, anywhere?

Thanks.