@Hope is life , SMEs are much smaller in size compared to mainboard and few bad quarters can lead to shutting shop.
In case of mainboard IPOs SEBIs approval (along with exchanges) is required, while in case of SME just the exchange (either BSE or NSE) has to approve the IPO, which means less compliance requirement.
Also, SMEs don't have to report financial numbers every quarter, they need to report bi-annually.
Due to all these things, LM's role in identifying solid business with good promotor background becomes very important.
Few notable LM's like Hem, CCV and few others do due diligence before the IPO process while few like Interactive just work for their fees without doing due diligence.