I understand most of what you are saying, except when you say "a more relaxed SS input". A valid experiment would compare the two cases at exactly the same entry conditions and exactly the same pilot inputs.
"a more relaxed SS input" was a veiled reference to once the desired trajectory is established it can be maintained "hands off".
With exactly the same entry condition,
as a practical matter, I don't think maintaining identical trajectories could be accomplished with 'exactly the same pilot inputs' to the elevator limits.
I understand what you're saying, that in ALT LAW with a somehow fixed THS setting, the FCS should 'theoretically' reposition the elevator as necessary, even hands off, to maintain the flight path up to the point the elevator reaches
'full travel'.
In practice, in ALT LAW, if the THS is somehow stopped at any position, when further movement would be commanded, the FCPC treats this as a jammed stab and will only exercise about 1/2 of the remaining elevator movement automatically, leaving the pilot about 1/2 of the elevator movement for manual control.
And of course to make the comparison in DIRECT LAW (non Nz) requires a whole different series of pilot inputs.
So I see what you're saying. I guess it would be correct if one considered the limit of elevator travel to be 1/2 travel.
FCPC's are wonderful things.