However, I didn't understand why you thought you could start once but not continue to run. Yes, the starting amps will climb a bit, but probably not more than a soft-start boost can handle.
Think of it as three separate things.
Step 1:
Starting the compressor is often expressed in the in rush current or the amps required to start the compressor, condenser fan, blower and move the refrigerant. This where the soft start helps. Instead of using just the power source amps to start the compressor. A soft start will use a start relay and capacitors to assist the power source in starting the AC unit. I am not smart enough to know what real mix is but let say for example, its maybe 75% power source and 25% soft start. Once running, the soft start is done. Soft start would be like hitting the electric start on a lawn mower and pulling the pull cord at the same time. Once it is started the soft start or pull rope is done. In rush current is like a choke on a lawn mower. It is always more very short-term fuel or amps to get everything moving than what's need to run.
Step 2:
Now that the unit is running. It is operating on minimum run load amps or RLA or in the case of our lawn mower, it is running on the minimal amount of gas idling.
Step 3:
The compressor is now seeing the load, compressing the refrigerant and releasing it into a cold vapor in the evaporator. The evaporator absorbs the heat from what the blower is bring to the evaporator. The evaporator transfers the heat to the refrigerant gas. The hot refrigerant gas from the evaporator goes to the condenser where it is returned to a liquid. As this work is being done it requires more amps from the power source, because it is doing more work than when it is first running. The RLA has to go up because it is doing more work. Same thing is true on a lawn mower. When you first start it. It only uses a little fuel but when you push it to cut grass it uses more fuel to cut the grass. If you push the lawn mower faster, it will use even more fuel because it has to do more work in less time.
FLA is full load amps, that is the max amps this unit should ever see. Most of the time RLA is 10 to 25% less than the FLA depending on the load. If The RLA is above FLA expect trouble,
. I hope this helps. I apologize for the long explanation. It's the only way I know how to explain it.