That would be great! Palawan is STILL relatively underpopulated. And if the Chams settled Palawan, nothing would likely stop them from settling on Borneo either. Checking Wikipedia, I found that there was a kingdom on Borneo named Po-ni that likely controlled Palawan and which the Chams would need to conquer. In fact Po-ni (Brunei) controlled the Philippines by the late 16th Century and had settled Manila. The Spanish had to conquer it from them in the 1570s.
So if the Chams could conquer and migrate to Po-ni, they could not only conquer the Philippines but the North and East of Borneo as well. They would have no reason to adopt Islam. Spain would either be butterflied out of East Asia or wind up conquering Taiwan instead of the Philippines.
And if Spain was butterflied out of East Asia, the Ming Dynasty collapses sooner, probably as a result of Hideyoshi's invasion of Korea. Because according to 1493, the Ming became very dependent on the Mexican-Peruvian silver trade to pay their army and civil servants as their currency inflated and inflated. If the Ming fell some time in the 1500s, the Manchus are not together yet under Nuranci and Dorgon and someone else founds the next Chinese Dynasty.
Of course the Vietnamese Nguyen Kingdom (Capital, Hue') could also conquer and settle on the Philippines and Borneo instead of the Cham and might well be motivated to if the Cham or the Khmer or the Thai prove a bit stronger. The Vietnamese are very short of arable land until the French give them the key to the Mekong Delta in the mid 1800s and with the right leadership might be looking to expand.