No, guess I wasn't clear. The Home Flex will be hardwired directly -- not using the 14-50 outlet, which will be extracted and become a junction box -- per code. The 60A is borderline between requiring 4 o 6awg wire, so I went conservative (perhaps above code) and installed 4awg. Yes, it's heavy wire to pull thru, but I only needed to go a few feet, just outside my service panel -- so it was not so bad (or costly).
I am all about over sizing the wire and outlets, I just ran 12awg for 7 outlets to hang 7 LED shop lights in the garage that will never pull more than 300 watts, but some day I have the option to add something more power hungry.