The SWD pin has been fixed when the chip out of the factory line, so the customer has no way to change the SWD pin.
But the SWD port pin can be configured as GPIO out of programming mode.
Notation such as Port 15[6:7] of SWD is described in various parts of the data sheet.
Does this mean that it was scheduled but not realized?
15[6:7] and 1[0:1] both can be the SWD interface.
But in the factory, we fixed one of them (1[0:1]) as SWD interface.
So we can ignore the other one.
one of our customers is using 15[6:7] since the beginning of P5 (before to be LP). He has a "special" connector (and cable) USB (as you know, 15[6:7] are USB line also).
Besides the two lines SW (CK and D -15[6:7]-), you need the reset (he connects the reset to the ID pin at USB connector). He uses the Miniprog3, using the 5 pin connector.
Of course, if you are using this method, you can't use the USB.
If I'm not wrong, he has the P1[0:1] configured as GPIO (because he is use them for other purpose)