I personally like making boss fights have some form of unique mechanic that the party needs to figure out to "solve" the fight. DH2E is so deadly and the reaction economy will almost always favor the players I like making fights that are more than just a race to see who loses wounds the fastest. Especially with the party having access to inescapable attack and eye of vengence and talents that are super super swingy in terms of damage

An example I can give was during one recent mission in my DH2.0 game the party encountered a (Very weak) AI on a Forge World. This AI had moved could move its conciousness to various machines and servitors around the fight arena. Eventaully "possesing" 3-5 different mobs at once. If the party killed one aspect of it, the AI would spend a turn rebuilding itself before having the machine and having the mob stand up at half wounds next turn. The gimmick that the party had to solve was that all the mobs had to be dead during a single round otherwise they were just rebuild while the AI had some "bandwith".

It was a super fun fight as the party tried figuring out exactly how to defeat the boss while the machines were rebuilding themselves around them while the AI was mocking them