Visited on October 23 and charged with M-CHARGE RFID.
The chargers are in the underground parking. There's no signage but I didn't see multiple paths possible, you always end up driving in front of the chargers.
Access to Migros is from Bahnhofstrasse. There's a Migros sign at the roundabout.
The chargers are EVTEC, but with a longer cable than usual. You should be able to park forward and plug in any car, assuming you can find a spot where your charge port is on the side of the charger. The Tesla that arrived while I was there did not attempt to plug in that way, and immediately parked backwards when it was probably not strictly required. You will most likely block your driver's door if the charge port is on the left though.
The chargers have the touch screen and power limit reason indicator. I had some difficulty waking the left charger from the screensaver every time, but then it was perfectly responsive...
There's a parking meter, 1h free. Since they repeated the store opening hours on the parking meter, you don't need to pay or use the meter at all when taking advantage of the 30 additional minutes after the store closes but before the parking closes. That's up to 1.5h free if you come in late in the day.