Problem with Chaos route is that it's strips you of too many good things while giving crap back.
The Edge of Daybreak sword should literally SHIT on every other energy sword to the point "It feels bad" not being a heretic while playing melee pyros.
For going chaos, you leave behind:
>Heinrix, second best companion and highest damage dealing one
>2 Soldier companions - Unless your RT is one, you'll have zero soldiers onwards.
>Lore:Imperium to HP% - This is a big deal for Executors - which means it FURTHER soldifies Psyker Heretics as inferior builds
>Burn on any crits during round 1 - this IS a big deal because otherwise you're forced to take AoE flame spell instead of control flame to spread it - ONCE AGAIN solidifies Heretic Pyro being shit
It'll half a year until they do something with Executor but so far Chaos route only gives you Strongest Officers because you can farm perils and put them on the enemies via Psyber. - This is literally the only good Heretic build.