Nope - There are no lock-in periods for smallcases. One can hold and exit their smallcases anytime they wish to. Though as a concept, smallcase works best for long-term investing.
And for Intraday trades - yes, since there is no lock-in periods, you can buy and sell the smallcase on the same day. However the Zerodha brokerage and other charges would be different for intraday trades.