some...the plant itself takes up water/nutes when ready...when you flush you are allowing the plant to drink, but not take up nutes...there are enough nutes in the plant,
to sustain it normally, imho.

If you vegged 2 months then usually it would be stop nutes and flush week 7and 8 with ph'd water...If using pro flush product;(final phase, or flora kleen) You can run nutes up until last 4-7 days...

don't know what BC strain is...is it indi or sati?

The pistils are only a guideline...the only true way to tell is tric's...you have scope...you are the Man! You have to make the call...If you see amber tric's, I think you can flush whenever YOU are ready. Goodluck, RV