considering an upgrade to a metal cage

I’m currently using a hT4 knockoff, which is the most comfortable cage I’ve owned so far. I’ve been wearing it consistently for two months now. The fit works well overall, but there are three things bothering me:

1. Body heat makes the resin soften up, causing the interlocking mechanism to get quite loose.
2. It feels a bit tight; specifically, the bottom of the tube doesn’t fully cover my frenulum and
3. At first, the urination slit was too narrow for comfort. I made some adjustments myself, but this might be trickier if I switch to metal later on. What I need is something that covers the lower part of my shaft, has a comparable base ring, and won’t warp under heat. Any suggestions would be great.