How long does it take for the air spring to reinflate? Should I wait till it reinflates before I take it off the jack stands?
I would remove the jackstands and lower the car to slightly lower than the stock height. While still on the jack, cycle the ignition key and allow the compressor to run. It may time out in 90 seconds. If so, repeat by turning off the ignition and then turning it back on. By the completion of 2 cycles it should be inflated properly to remove the jack. If not, investigate for a leak.
You need to buy another fuel filter.