simba has also 30/50 GB plans for malaysia but roaming is weak.
However, i noticed for malaysia, it's not data size that matters, choosing telco is more important. Many buildings and remote areas has poor reception if u drive around, so need to choose a Singapore telco that works with a reputable telco in malaysia for roaming. Chatting with malaysian ladies on Whatsapp sometimes a challenge in Malaysia.
If you enter malaysia every month, can try applying for esim with the top 3 telcos - Maxis, Digi, Mycelcom.
For single trips, there are also a lot of kuku brands selling tourist esims (need to activate when u reach malaysia).
https://www.lazada.sg/tag/malaysia-travel-esim/