From what I read the slow charging is part of the cold weather issue but it no different than the NCA packs, there is a German Youtube channel "nextmove" that did extensive testing, unless you speak German have to use subtitles, but they found that after the software update the charge rate was pretty much the same, and both cold NCA and LFP batteries are slow to charge and loose range. The quick drop in range reported by the car on LFP was essentially bad pack calibration due to the LFP's different voltage curve, when they measured the actual driving distance they got out of the pack it was as expected. The software update and charging to 100% seems to have fixed this, bad on Tesla for not fully testing the algorithms for the new packs, but it looks like it was just software not a pack issue. They did roll out an update which looks to have corrected this.