Before getting so hopeful with Philippines territorial claims using UNCLOS a maritime agreement, kindly check the content of Treaty of Paris.In the short term, maintain access to resources in the disputed areas.
in the medium-long term, maintain a military presence so it has a seat at the table in any future reshaping, either in the form of a formal CoC, or in a post-WW3 Asia.
It’s always helpful to have a bargaining chip. If the US wins, chances are the Philippines will be given its claims in the SCS. If China looks like it’s going to win, they can negotiate neutrality in return for some of their claims.
Their biggest risk is backing the US to the hilt and getting punished for it. But they’re not so far down that road that they can’t back out.
Always remember that US is not a party in SCS.