Welcome in the forum.
The Register TRMs are 500 page documents which will not reflect capabilities of the capsense components. These "Registers" mainly describe the area within the PSoC chip to access the very basic hardware as wires, UDBs, ff-blocks, SCBs, clocks and some more basics. The capsense is a mixture of hardware blocks as DACs and a lot of software. As you can see there are two different capsense components which use different implementations. I would suggest you to stick to the capsense datasheet which explains in depth which functions you can use and what variables (registers) the software maintains.