Bear in mind, the signal “bars” are a relative measurement, the only way to be sure is to look at radio debug and see signal strength across all bands the phone is connected to at the time.
However, that leaves out 14,25(superset of 2),26,29,30,46,48,66(superset of 4),71.
14 and 71 are necessary on AT&T or T-Mobile respectively for low band coverage in some markets where they don’t own band 12 spectrum, the others are more capacity bands on the various carriers, but with the shift to 5G, they’re more important on a phone that doesn’t support 5G like Pinephone Pro.
Bear in mind, the signal “bars” are a relative measurement, the only way to be sure is to look at radio debug and see signal strength across all bands the phone is connected to at the time.
According to the FCC SAR report: https://files.pine64.org/doc/cert/PinePhonePro SAR Evaluation Report-S21101902806001.pdf it only supports LTE bands 2,4,5,12,13,41 in the US, which overall isn’t terrible.
However, that leaves out 14,25(superset of 2),26,29,30,46,48,66(superset of 4),71.
14 and 71 are necessary on AT&T or T-Mobile respectively for low band coverage in some markets where they don’t own band 12 spectrum, the others are more capacity bands on the various carriers, but with the shift to 5G, they’re more important on a phone that doesn’t support 5G like Pinephone Pro.