I don’t know anything about the Apprentice S.
My guess, the switches changes what mode the Rx is in with a given Tx switch positions.
I believe SAFE has 3 modes, beginner, intermediate & experienced. If your Tx only has a 2 position switch, you could only reach 2 of the 3 modes.
The experienced mode is just minimum SAFE, full control surface movement and less expo with no angle limiter or self level, see below.
If you set your transmitter up properly (see instructions) you don’t need to use the jumpers on the receiver, it is by default set to all three modes, you just need to put a switch to the correct channel on the TX to control it. Position 1 is usually full safe, 2 is intermediate and 3 is expert. The little switches just alter what modes are sent via that channel.
You can experiment for yourself the differences between the modes. On the ground, take the prop off, hold the plane in different angles and see how it responds to different modes. Give the plane a quick jerk and see if there’s a response in different modes.
I don’t have firsthand knowledge about SAFE. My understanding is beginner limits the bank angle to something like 30 degrees. Intermittent gives you more bank angle. Experience removes the bank limits. There may be differences in stability and auto level as well. Stability corrects for a wind gust to bring the plane back to the original angle. When the sticks are neutral, auto level will level the plane. There may be different combinations of stability and auto level in different modes.