Microphonics arent a major issue with the crossovers.
And so long as everything is securely mounted to the a board with zipties and hot glue, there's not much thats going to affect them sonically in that regard.
Cabinet resonances and a ringing woofer frame are going to have a much larger effect on sound quality.
More sensitive equipment, like turntables and tube gear, are much more susceptible to microphonics than anything found in the crossover.