Recommendations for UHV-Compatible Coax-to-PCB Connectors

I was reading Milan Yogendrappa’s article on mitigating outgassing effects in PCBs. I was also curious, I’m currently looking for coax-to-PCB connectors for use in a ultra high vacuum setting, does anyone have experience with sourcing UHV-compatible connectors?

Are there any issues with standard gold-plated connectors with PTFE insulation? For pop-on style connectors like SMP/SMPM, are internal air pockets a concern for virtual leaks or outgassing?

Thanks in advance!