Hey @Alex-Kushleyev how can I get on that mailing list for the ModalAI sanctioned mast? I designed and 3DP two mounts and used a carbon fibre rod, along with a copper laminate board and seen great improvement in GPS count (see image and screenshot).
Did a couple test flights with this set up and everything ran smoothly. I'll have a better peace of mind with an official mast though.

Looking forward to your response!