In passively-crossed-over, or worse, single driver systems, I have
never heard a SE tube amp that sounded better than a probperly designed
and built push pull one. I can't categorically deny the possibility of
their existence, but I have heard a LOT of homebrew SET amps and their
full range performance has been universally mediocre at best.

I will concede that given a OPT specifically designed for the job a
SET might work well for a tweeter amp in a bi-amped (true bi-amped,
actively crossed-over-NOT musketeered!) setup. Such a OPT doesnt exist
and despite lip service from several known suppliers (besides the known
sociopath from Philly, who is not credible on any level anywhere) no
such part exists. They admit (substantially) all their customers are
electro-ignoramuses who can BARELY build a SET, let alone any more
sophisticated amplifier, and are running full range because it's simple
and gives 'the rolled-off "antique radio tone" they love'-i.e. the
antithesis of high fidelity.