Flying PER-SIN (SQ Y) connecting to KUL (MH J)
2 hour connection

Per the SQ page, it seems they will check my bags through, but there is one line that concerns me....

If you are transferring/transiting through Singapore, you must ensure you are booked on a single itinerary. Read more about transiting in Singapore here.

The URL gives error 404 so cannot read more about this limitation. No visa issues with entering Singapore, and if this does not work might decide to have an overnight landside