Before he passed away, my uncle owned an automotive garage. My dad and my
uncle had a conversation about front end alignment. Evidently, whether the
driver is in the car can play into that. How much is this reflects on a
riding mower's toe-in, I'm guessing much more. So, put a few of bags of
sand on the driver's seat before checking toe. Put that in your pipe and
smoke it. Rest of the clowns too.
Dave

You're absolutely right Dave! On a vehicle with independent suspension
like most cars and trucks, the toe is affected by the vertical
position of the wheel by virtue of the geometry of the suspension.
I've always been sceptic about the method of aligning an empty car.
When the heck is a car empty while it moves??? I'm having no more of
that. My crown vic had its first alignment at 70k and showed a slight
more wear toward the inside. After the "aligner" told me he did not
need to touch my toe, I told him to please pardon me for asking him
for removing 0.1 deg to the toe. He asked why, then told him that you
can't tell people to get their car aligned so their tires last longer,
and at the same time completely ignore wear on the tires when the car
is aligned "right"! He reluctantly removed the .1 deg, and now my
tires wear evenly. Your Uncle knew that.

A garden tractor is has no suspension Dave, hence toe is unaffected by
load.
This clown rests its case.