The elephant in the crown court
must be how to conduct jury selection with 40 members of the public while a jury is assembled, get the defendants into a court (in some cases there could be as many as 20 defendants plus barristers plus solicitors) plus ensure the mentioned right of the press/public to attend every day.
To do this and to ensure that everyone maintains a 2 metre safe distance is going to be a mammoth (excuse the pun) task. One aspect might be to guarantee a defendant a maximum 12 month sentence, thus ensuring that the case could be handled by a judge on his/her own. This could still involve legislation since the right to a jury trial is enshrined in UK law.
Perhaps the use of specially created courts with very large courtroom areas, where all required members can sit in protected transparent booths.