This [0] is the closest we have so far - almost entirely FLOSS, and it consumes ~1/4 (IIRC) the power of the stock firmware.
It's also never going to be the default Pine64 ships with, because no OEM wants to tell the FCC "We asked the users nicely not to send erroneous signals. No, this was not lab-tested, nor verified by the FCC to not interfere with other devices."
Considering the legal limitations, I think this is an absolutely amazing point to have gotten to. OP may have issues, but he mentioned even his Android handset had similar issues. I have a pretty good carrier (for a carrier), amd have pretty well no issues using my Pinephone Pro as my actual smartphone. I just carry a spare battery :)
It's also never going to be the default Pine64 ships with, because no OEM wants to tell the FCC "We asked the users nicely not to send erroneous signals. No, this was not lab-tested, nor verified by the FCC to not interfere with other devices."
Considering the legal limitations, I think this is an absolutely amazing point to have gotten to. OP may have issues, but he mentioned even his Android handset had similar issues. I have a pretty good carrier (for a carrier), amd have pretty well no issues using my Pinephone Pro as my actual smartphone. I just carry a spare battery :)
[0] https://github.com/the-modem-distro/pinephone_modem_sdk