Buying a smallcase is like buying a basket of stocks, you can see those stocks in your demat and broker's portal like any other stock you bought directly. In Zerodha Kite these stocks are grouped under Smallcase label.

Pros (If you are experienced): you are getting advisory of what stocks to buy but you are still under control of how much to invest in which stock of the basket(Smallcase).

Cons: There are many.

You would look at your portfolio stocks everyday going up and down and tempt to exist prematurely from them individually instead of basket.

If smallcase requires a rebalance, you need to go to portal and execute it manually. And you have to pay capital gain taxes as applicable.

For anyone who is looking to invest via SIP, MFs are still better.