I’m certainly willing to pay $100 more for a phone that has a replaceable cellular modem, because I care about the environmental impact of electronics and planned obsolescence, but it is important to understand why no company did it before Purism. Todd Weaver is truly unique in the hardware industry in what he is willing to do to run a Linux kernel without binary blobs. Purism is going to extraordinary measures by running the Wi-Fi/Bluetooth over SDIO and the cellular modem over USB+M.2, and putting the binary blob to initialize the LPDDR4 RAM in a separate Flash memory chip and running U-Boot on a separate Cortex-M4 core in order to execute that blob.
Frankly, I stand in awe of the company, but I can’t see any of the other Linux companies doing the same, because you need a company that is really committed to the ideals of Free Software Foundation to do it. If the Librem 5 becomes a huge commercial success, we might see copycats, which would be fantastic, but the economics are not in our favor.
Sorry, but they are the only options. As I explained in my previous post, nobody makes a cellular baseband chip package that is smaller than 29x32x2 mm because you need a giant heat spreader to redistribute the heat, so you are either stuck with a 30x42 mm M.2 card or a 30×50.95 mm mPCIe card. You can’t use the smaller sizes because the chip package won’t fit on them. If you have better cooling, then you can use a smaller chip package, but how are you going to implement better cooling on a plugin card? Even if you create a custom chip socket to put on the motherboard, how are you going to attach the cooler? Remember that Purism is a tiny company, so it can’t demand custom form factors from suppliers.
Purism is in a bind here. I assume that Purism didn’t select the Quectel EG25-G for the Librem 5 which supports 30 bands, because it required some binary blob, whereas the PinePhone is using it because Pine64 doesn’t care about free software. However, the reason might be because this chip is only available on mPCIe cards, and Purism couldn’t find another 8mm of space.