How does size impact smallcase:
1. If the smallcase has smallcap stocks whose average daily volume is really low then if you tried to trade an order of a few lakh via market orders you'd get a very bad execution price
2. Even if the portfolio does not contain smallcaps, if your portfolio size is too large, say more than 50 lac, it might be ideal to slice the trading into smaller orders (which smallcase does not allow)
Wright Research smallcases contain mostly highly liquid stocks (except for Wright smallcaps) and we haven't seen any problem for portfolios as large as 35 lac on smallcase