look at the specs of the BC stage 2 cams, if they are comparable to JWT S3 or S4 Cams, or Tomei Pon cams then NO you do not NEED a tune.
But getting a tune after said will obv increase ur power, prbly make the engine run smoother as well. it is suggested, but not necessary.
Eno had exhaust intake and header with bcstg 2 and he intact did need a tune.
His factory tune was dangerously lean. However his engine never blew up and made almost 160whp brakeing up from factory tune