Having flown SIN-KUL-SIN this past week, I can confirm that:
- At SIN, OWE can get emergency exit row seats assigned for free at check-in, just requires a simple phone call to the seat controller.
- At KUL, the check-in person insists it can only be assigned to MH Plats. While standing at the Business Suite check-in zone, she even asked me to walk around to her computer screen where it showed the price that appeared for my booking (RM39) and said there's no way for her to override that.

As to why there's a discrepancy in approach... well, go figure.