I’m trapped in Codex

I have the old grandfathered $200 plan 20 X. Even though right now using Codex eats through the credits like the old hundred dollar plan. I’m hearing all these beautiful things about opus 5.5. I feel like I would love to switch to their $200 plan but if I leave Codex I forfeit my 20 X. And given how things go, the tides could turn back to Codex. I feel trapped on my 20 X Send help