Looking for some assistance

Hi to the masses! I'm looking for a little help with my build. I followed the build of CaptainLance for a RF Chieftain (https://www.youtube.com/watch?v=2pmvqB4T_Bs&t=308s). This build is really great, but at this point I find myself unable to quickly and reliably delete the T14-16 bosses.



Here is my POB, hopefully there are some things you more experienced folks can see to help: https://pastebin.com/iHaaCwni