Shouldn't matter (Memory stick or Direct Connect)
Just make sure you set up the "Timing Location", click on the Start/Finish box for Timing Location 1. Then click on "Allow Mixed".
There are no additional timing locations and you have 1 "Finish/Split occurrence.
I have been using this set up for probably 15-20 races since the pandemic started and we went to "rolling starts".
I have even used this with a race where they crossed the mats for a split at the halfway point of a 6 mile trail race.
As Ed stated, wave start by participant, then check the box for "consider chip time as the wave time".
Do not set a gun time.
Everyone will have the "time of day" as their wave time, then under "Occurrence" it will show "S" for the first time they cross the mats and "1" as the second time. You'll easily be able to pick out someone who's start time doesn't look right (missed read).