Bright mod does change the cap value in the RC circuit to change the cutoff point.
Here's Juansolo's Shredder, you can easily see where it's wired to the DPDT switch.

Here's mine, in a bigger box, which also has asymmetric/symmetric diode clipping on the switch on the right, this replaces the two back to back diodes on the board.

Sometime I will replace the HUGE cap, it was all I had at the time.
You will also notice the lack of small box caps, just the big boiled sweet looking ones squeezed on there.