I’m sure your guys have done a ton of prior art, but I want to encourage you to make sure Amazon hasn’t patented this in any capacity yet.
A close friend that worked at Prime Air shared how years ago their division had a full time legal staff dedicated to patenting all engineers ideas. He had gotten several patents even being entry level FWIW. They had several concepts very similar to this and it wouldn’t surprise me if they were able to get that IP locked down. Like I said, I expect you all have checked and rechecked but thought it’s worth mentioning.