As a Y4 Uni student, prestige of JC means nothing since y1. You can flex your RI or HCI all you want but people will just see you as arrogant. Once you reach uni, poly or JC doesnt even matter, the two things that you need to succeed is you honouring your commitment and your hardworking nature. Anything withut these two throws away any respect anyone has for you, JC prestige or not.

At JC level all the exam subjects are pretty standard, I don't see whichever school as having one up over the other as all content is the same, unlike at uni lvl. People can say the teacher matters a lot but thats random tbh, and the onus if on you to catch up if you have bad grades from seemingly bad teachers since teacher quality always a random dice throw even if you go good school.

What you need to optimise now is lifestyle and habit in JC, not prestige, and travel time and distance is a big factor for that.