hi.
tell me please:
because of technical needs, I need to interrupt and to launch again a mainer through 1000 shares
whether my profit will decrease?
no; since you are a ratio; its only the downtime that will effect you... you should be ok.
I do suggest letting it run for the maximum amount of time; record what the difficulty gets to each time; average those numbers, and use that as a manual difficulty in your password string. This way difficulty doesn't need time to adjust every time and keeps you optimal. Just average ~5 different restarts.
Example password:
c=BTC,nist5,d=4