Concourses need to be closed in my opinion. EP actually works well in that all sides can be accessed from outdoor areas. Of course people would need to be advised against 4 pints beforehand!!
I think the bigger problem is complying with the testing regime for players and staff. I believe all Prem and Championship players get tested twice a week at a cost that just makes it unviable for most clubs at our level. I'm sure there would be ways to get some fans in including making the RE useable again because that really is outdoors, but think the NL and below are caught like a rabbit in the headlights when faced with the potential testing costs.