One shop in my city is open for three hours two days a week.  During these shifts, they have two or three volunteers in the shop to do minor repairs on a PWYC basis, and to sell new merchandise.  The rest of the week is dedicated to building bikes.  Volunteers coordinate so as to make sure too many people are never in the space at the same time.  They also have a nascent youtube channel and offer some seminars on Zoom.

 

Another shop welcomed volunteers for part of March and April (until the stay at home order was issued in my city), max of five people in the shop at one time.  This shop also provides a repair service for the community, so people can drop off their bikes and pick them up 48-72 hours later.