No!
Use the LM2956 to provide the regulated voltage you need but not to control the LEDs. It isn't designed for pulsed operation, it is designed to give a steady voltage all the time.
Bear in mind, based on your other thread, you can use much lower voltage to power the filters and comparators circuit, they draw negligible power, and if you use a MOSFET as the LED switch, you can run the LEDs off unregulated power and avoid the need for a complicated power supply altogether.
Brian.