When it comes down to it, the strut and the 4x4 are equivalent
in terms of being paranoid about it turning sideways (the strut
perhaps being a little more likely in terms of less friction).
Both are more than adequate in terms of strength.

In my case, it'd be pretty difficult for the 4x4 to spin because
it's partially wedged in place with parts of the roof truss.

But still, I'm fussy, and "finishing" the job will entail a couple
of #8 or #10 screws tied into the trusses.  If nothing else so
it won't move and disturb the rest of the ceiling.

You could do that with the super strut too - drill a couple of small
holes and poke a few #8s or #10s.  [predrill the trusses if you're
paranoid about splitting.  As long as you don't split 'em, a few
screws won't hurt the trusses.]

There are situations where super-strut would be preferable to 4x4s
for this application, but 4x4s are cheap, plentiful and perfectly
adequate for most situations.

_Whatever_ you use for support, I do strongly recommend that you
don't have the eyebolt (or whatever you hang the hoist on) extend
below the 4x4/super-strut any more than just the eye of the bolt itself.

If you use let a long eyebolt protrude, say, 4" below the support
beam, and have your load swing perpendicular to the support
beam, the support beam may rock (increasing the possibility of
slip) if the beam isn't fastened to the trusses, and potentially
fatigue-break the screws/damage the trusses if it is fastened to
the trusses.

In other words, keep the swing arm supporting the hoist as _short_
as possible.  You can use a quicklink like I did, or a few links
worth of proper chain.  Or maybe the top hook on the hoist makes
it unnecessary.