How To Quartet Practice With Social Distancing

The wife says they all have to be close to each other to be able to harmonize the way they need to. That’s Kinda hard to do and social distance at the same time. Options? (a.) No more practices until this pandemic is over or (b.) come up with a way to be safe and make it work.
My solution was wireless microphones and wired headsets while staying at a safe distance apart. I color coded all of the cable connection’s, Mic’s and headphone’s so no one touched a component that wasn’t meant for them. This system allows them to hear themselves collectivelyas if they were close to each other. The hangar was the best place to use it.Couldn’t use wireless headphones because of the inherent Latency or delay they all seem to have. Some are less noticeable than other but all that I’ve seen, seem to have it. The wireless mic’s works fine though.
There are several ways to do this. I used two rack mounted units I found on Craigslist. A VocoProUHF-5800 wireless microphone system and a CARVIN H400 Four Channel Headphone Amp and bolted them together to make them portable. I found some good headsets and cabling on Amazon. The headsets are MaonoBrand and seem to be very good quality and were reasonably priced.
I recorded their music using my BehringerEurorack MX802A Mixer between the Headphone Amp and my laptop. I could have bypassed the mixer but I felt I had better control with it in the loop.
They all say it’s not as good as standing together but it ain’t bad.
This is a cellphone video of them using the system. The audio heard is not thru the system though. It’s what the phone heard during the recording.