On PS inductor resonance, it is not a bad practice. One LC stage to remove nearly everything but a 120 cps ripple, then a second LC with a tuning C shunted across the L to establish its resonance at 120 cps. Nearly pure DC is the result.

The numeric analysis would seem to idicate such a widely varying load on the driver stage would be bad news...these are ov course the same methods that would have us using SS for amplification...:)
cheers,
Douglas