FYI, any Arduino is NOT a good source to learn best design practices. Or OSHW for that matter. They copy stuff from each other, without really understanding what is going on. For example it is possible that you need the resistors for FTDI, say FT232D and they just copy it and use it for the FT232H, which doesnt need it, and then it is copied by a chinese engineer, who replaces it with a CP2102N, because it is 5 cent cheaper than the FT232H... And so on.
The difference is that everyone can tell apart a shoddy shed and a proper house, but it takes a bit of insight to spot bad electronics design.