Winterizing hybrid pool - Do I need a pillow if I don't use a cover?

Hey guys, do I still need to use an air pillow if I don't use a winter cover when winterizing?

Is the air pillow people use to prevent the water on top of the cover from hurting the pool walls, or is it to keep the water in the pool from hurting the pool walls when it freezes?

I have a 4ft x 4ft air pillow that came with my pool, I can put it in no problem and tie it in the center of the pool. I am not using a winter cover. I have the water drained to about 2-3 inches below the returns. The returns are plugged with PVC pipe plugs. All of the pool interconnection lines have been removed (I have an above ground pool with in-ground lines), the in-ground lines blown out and a gallon of anti-freeze poured in each one as insurance. The lines are 2" PVC with 3 lines total with a length of about 74ft per line (so over 220ft total of buried lines). Al three are capped at each end.

I also pulled the main drain piping and poured 3 gallons of anti-freeze down the line, blew into it to drive the anti-freeze below the shut off valve and capped it. The main drain is a dual anti-entrapment drain positioned 5ft apart with 2" PVC line tee'd together and 2" PVC line running to the perimeter of the pool. 3 gallons may have been a bit much, but I wanted to make sure there wasn't going to be any issues.

I drained and removed all the water from the cartridge filter, gas heater and pump. I was in a frantic rush to get all this done last Tuesday as it was the last day above freezing with the temps dropping quickly throughout the day (ended the evening with 27 degrees overnight), so I still have to get the equipment put into the garage, but I did pull the pressure gauge off the filter so it wouldn't freeze. I got so late on winterizing because I was still finishing off aspects of the paver patio and garden circle (and the garden circle is only done just around where it meets the patio. I still have 40 blocks to lay for the remaining circumference of the base and another 100 or so to glue onto the base once completed. Not to mention the 165 bullnose pavers I need to cut (each get cut three times to make it fit properly) for the top cap.

So, I did good I assume?

What about the pillow, without a winter cover, do I need to worry about it?