Port Forwarding on CGNAT and Bridge mode

I love the T-Mobile service but need to do port forwarding for a Raspberry Pi running Echo Link and AllStar. I am getting a IPv6 address from my T-Mobile account. This is a question: If I could put the T-Mobile Gateway in bridge mode, tell my router to use IPv6, would it let me set up working port forwarding and use IPv4 on my Local Area Network? Gracias