Which simulator you use mainly depends on the task you handle and your budget. I cannot recall there is free PWL simulator. For SPICE, LTspice and Qspice both handle switching circuit, and both created by Mike Engelhardt, and both are free, and with community support.
Ideal Switches in QSPICE - QSPICE - Qorvo Tech Forum
Frequency response analysis (whether calls FRA or .bode), is generally time consuming, as the frequency range you interest normally much lower than switching frequency, and as a result, require long simulation time. So, @physicboy said it is quite common people need hours to simulate that for a complex system.
Just in your case, as crossover is somewhere 100kHz, you just don’t have to down to 1Hz to waste a lot of simulation time and memory storage there. Generally, 2 decade before crossover and 1 decade after crossover is good enough.