I know absolutely nothing, so of course I would like to speculate!
I think it would be fairly easy to reduce the number of guests in Savi's per "show," and have clean trays / parts / crystals ready for use. The down side would be CMs handling multiple guests' hilts - but I'm pretty sure I've seen in videos up to 6 Gatherers on hand plus the lead Gatherer/presenter, so if they took 7 Builders per session (instead of 14), each Gatherer could assist one builder. Add some hand sanitizer and maybe gloves for the Gatherers, and I think you are good to go. They could even explain the CM masks as part of the "secrecy" of Savi's. They could also find a way to display the sample pieces outside so people can't touch them.
The first key to Droid Depot would be limiting admittance to people with reservations to build (including any allowed guest/parent) - no general retail shopping/browsing. They already have a big case/display where you can see all the available parts on the wall. They would need to block guests from the conveyor belt - CMs only. Builder looks at the parts display on the wall and makes his/her choices. CM "Tech" enters the "parts order" on a "data pad." Builder proceeds to where the Techs are working at the conveyor belt. One Tech gathers up one Builder's parts order in a basket, comes out with it and escorts Builder to a work station where Tech assists Builder with Droid. Again, lots of hand sanitizer around, maybe some CM gloves, and "workshop masks" in character. Seems totally doable.
At $200 per lightsaber and $100 per Droid, I would think Disney would want to keep these open.
