I'm pretty sure the topcap isn't an issue. There's a few mm of stem above the top of the steerer (I know it's better to have a spacer on top of the stem but this is how the bike shop built my bike. If i can't get this issue worked out I may see if using a positive rise stem slammed with a spacer above would help). Part of the issue was the compressor plug pulling up, but I think I've handled that now (is there a recommended torque for that?)