Indeed! At the frequencies and signal levels in pedals, most of us would be hard-pressed to hear the difference between any of the capacitor types. That being said, the last thing I want is for any component to make unexpected changes to the sound. Ceramic caps can be noisy, and the ones rated below 100V have such thin dielectric layers that they are unreliable long-term. I use silver mica, polyester or polypropylene film and tantalum for the electrolytics. The only place I use aluminum is for values above 47uF. Silver micas are kinda chubby, so I use them sparingly, only for values below 470pF.