Suggestions for my RF-Chieftain

Hello guys,

i am playing an RF-Chieftain since leaguestart and i have investet everything into it because its soooo much fun.

Now i have come to a point where i dont know what to upgrade anymore.
I wont start a new char this league and will spend everything i get into this one but i wont have the currency for mirror tier items.

So i thought lets ask the community what i could upgrade to be more tanky and do more damage.
Dont get me wrong, i am tanky as hell and i have about 10 mil single target DPS, clear speed is also amazing thaks to hinekora and bereks respite but there is always room for improvement.

(i thought to respec the area nodes on the tree to get more life/ damage. I have no idea if a cluster would be sufficient because i dont have alot of points to spare)

here is my POB:
https://pastebin.com/hQwZSSgs

and here the char on poe.ninja:
https://poe.ninja/builds/ancestor/character/xGLYDERWORMx/BeeftainGoesBoom?i=14&search=uniqueitems%3DBerek%2527s%2BRespite

currently playing to reach lvl 100 the first time (lvl 99 right now).