The document ESP32 Chip Pin List states the following:
Have I understood it correctly that any pin of any function can be remapped to any GPIO? For example, is it possible to remap VSPICS0 to GPIO16 and VSPICLK to GPIO17?The page "GPIO_Matrix" is for the GPIO-Matrix. The signals of the on-chip functional modules can be mapped onto any GPIO pins.
Some signals can be mapped onto a pin by both IO-MUX and GPIO-Matrix, as shown in the column tagged as "The same input signal from IO_MUX
Core" on the page "GPIO_Matrix".