I don’t get why you keep hoping that China won’t response to an existential crossing of the red lines.
Well, they haven't respond well to the things that Japan and US have done so far near Taiwan. Just look at US newest bases at the northern Philippine island. China failed to bring respond that can make Marcos to cancel his treaty with US. Their harassing Pinoy fishermen in SCS can only bring patriotic respond from Pinoys. Not Fear from them. And what China do to give message to US to an extend that they have to think twice before making a more aggressive stand near China?
1. I think what China need is a move that can bring FEAR to Pinoy more than make them feel annoyed and more patriotic. Whatever it takes. I think there is a country that hate Pinoy more than they hate China. It is Malaysia. Because Pinoy claims Sabah in their latest map. Create a Philippine pivot to the table. Yes, I know that Malaysia is closer to UK than China. But right now, Philippine has threaten their national integrity, and I'm sure US and UK will prioritize Pinoy because of China.
2. Use China proxy in ASEAN, like Cambodia, Myanmar, and Laos to attack Philippine in ASEAN meeting. Accuse them as a trouble maker that bring chaos the the peace in South East Asia. I'm sure another ASEAN Countries like Indonesia will also think about the provocation as a trouble that can break the peace in South East Asia. So play well in this diplomacy route to push Philippine in diplomacy area.
3. STOP China harassing Pinoy fishermen in SCS, because that move really useless. Rather that bring fear to Pinoy, it make another ASEAN countries to be more wary to China, and may bring them to the US camp. To be honest, China need to resolve 9 dash line claim with another ASEAN Countries beside Vietnam and Phillipine better. If they can return a mountain to Vietnam when they want to normalize their diplomatic relation, then why not some sea to Malaysia?
4. IF China can, just bring Moro and another Pinoy rebels to the table again. Give them more AK47, Anti Tank, and Manpad to give more headache to Philippine government. And when the Government throw missiles from above the manpad range, China can bring propaganda about Pinoy killing Muslims in Philippine.
5. Bring H-20 to the table quicker, to give message to Japan and another US-Allies in South East Asia. And make a video about it shooting a very big missile like FAB3000 to convey the messages.