Whether to use the precessed method of calculation for the return charts is still a subject of controversy.
A precession of the chart takes into consideration the precession of the equinoxes since the time of birth. What this does is advance the Natal planets in the chart very slightly as you age.
An example of this, is a planet that is at 2 degrees 16 minutes of a sign at the time of birth… over time it might advance by middle-aged to 2 degrees 56 minutes. The older you become the greater the difference between the two.
This is why there is such a difference when calculating the Solar Return using precession. There is sufficient evidence to show the precessed charts tend to show circumstances as they are experience on a more psychological level. When using a non-precessed chart, the pattern seen here are the way the person experiences events in a more material way.
Depending on how you like to read your Solar Return depends on which chart style you choose. I don’t feel that there is a right or wrong way of setting this up, it depends on the individual.