Welcome. Glad that you stopped here to ask your question.
I can't answer since we haven't traveled with our DD since March, but at least my answer will bump your question up.
My guess is that it won't take much longer to check the wheelchair/stroller than it did before. The security people usually took about 5 minutes to check our DD. Since she can't stand, they leave her in the wheelchair. They had her lean forward so they could check behind her they also patted down her legs, arms and back and looked under the wheelchair. Sometimes we wait a few minutes for them to get around to checking her. That's probably the part that would take longer. I have seen people send folded up umbrella strollers thru the Xray machine. If your daughter can walk thru the metal detector and the stroller will fit thru the xray machine, that might work for you.