"Use colour from tab" for tree path highlights was only working for colors that come from tab-linking. In 12.0.12 it will use custom tab colors as well.
For photo import speed, we need more details of what you're doing. Preferable in a separate thread. (See ask one question per thread for suggestions on when to use separate threads.) If you are connecting to the camera via MTP, toggling Preferences / Miscellaneous / Advanced: mtp_enable may help; failing that, plugging the memory card into a USB card reader should give faster results than MTP in general.