Tony writes:

However, if you while coordinating rudder and aileron you put
forward pressure on the yoke, you can take off those G's -- push hard
enough and you can probably go to negative g's and only have the seat
belt holding you down. So, there is some forward pressure that will
just compensate for the additional g's the coordinated level turn will
cause.

The additional Gs are unavoidable in a coordinated turn at constant
altitude. They arise from the fact that you are being accelerated not
only downward by gravity but also towards the center of the turn by
the aircraft's bank, which essentially uses part of the lift provided
by the wings to accelerate the aircraft inward. The bank insures that
the resulting acceleration vector remains normal to the wings (and the
aircraft's occupants), but its magnitude must increase.

If you do nothing to maintain altitude, you can stay at one gravity of
acceleration, but you'll descend in the turn.

In a barrel roll, you cannot avoid accelerations greater than 1 G at
some point. At some point, the aircraft must descend, and then level
out. At that point the acceleration will exceed 1 G.

You should be able to make the additional increment of acceleration
arbitrarily small, however, at least in theory.

Do simulators allow the inclusion of a three axis G
force meter on the panel?

Not that I've seen, but there are many simulators in the world.

In MSFS, you can do a barrel roll while monitoring vertical
acceleration. If the acceleration stays positive, you're good. If it
stays close to 1.0, that's better still.

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