I'm looking to book SIN-KUL, and KUL-SIN-XXX as two separate tickets, with the SIN/KUL sectors either on SQ/MI. The J fares out of KUL are fantastic! Can do this without a checked bag.

Understand airside in KUL is similar to SIN. To avoid having to go through immigration (and while being on separate tickets), guessing I can do OLCI for KUL-SIN and show a mobile/printed boarding pass once I land in KUL? I recently had a friend doing a similar transit in KUL and was told by SQ staff that he had to exit, go through immigration, and use the regular check-in counters.

Has anyone experienced a smooth transit on SQ on 2 separate tickets at KUL using OLCI? (or other tips?) Thank you!