I found that side focus just doesn't work well for me.

It appears that front AO is a parallax adjustment .. I can dial out the parallax. It isn't just focus.

The side focus, in my testing, was only that, focus. It had no impact on parallax.

Others' mileage may vary I suppose.

Anyone who thinks there's two sides to everything hasn't met a M�bius strip.

Here be dragons ...